Aptitude - Time and Distance - Discussion

1. 

A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?

[A]. 3.6
[B]. 7.2
[C]. 8.4
[D]. 10

Answer: Option B

Explanation:

Speed = 600 m/sec.
5 x 60

   = 2 m/sec.

Converting m/sec to km/hr (see important formulas section)

   = 2 x 18 km/hr
5

   = 7.2 km/hr.


Abhi said: (Jun 3, 2010)  
What's the formula?

Shikha said: (Jun 5, 2010)  
From where you got 18, I don't understand.

Sundar said: (Jun 5, 2010)  
Hi Abhi & Shika,

Kindly go through the basic formulas for solving Time and Distance problems.

Have a nice day!

Rajasekaran said: (Jun 18, 2010)  
How that 18 came?

Mallikarjun said: (Jul 2, 2010)  
1km/hr=(1ooo/3600)m/s=(5/18)m/s
for converting m/s into km/hr 18/5 is required to use

Yuvaraj said: (Jul 9, 2010)  
I don't know the formula. How you convert m to km. What s that formula.

Sushree said: (Jul 16, 2010)  
Where we got 60 there?

Mohit said: (Jul 18, 2010)  
Before attempting questions kindly go through the formulas.

Deepa said: (Jul 21, 2010)  
Can anybody explain me the step 2.

Piyush said: (Jul 23, 2010)  
In step 2. There is conversion of m/sec to km/hr.

Vidu said: (Aug 4, 2010)  
From where the 60 came?

Sundar said: (Aug 4, 2010)  
Hi Vidu and Sushree,

You questions is from where did 60 come?

Please concentrate on the unit name mentioned along with the numbers.

Speed = Distance/Time

Here Distance = 600 meters and Time = 5 mins.

Therefore, Speed = 600/5 meters/minutes.

We have to write it as in terms of meters/seconds. So we are multiplying it with 60 (1 min = 60 seconds).

So, Speed = 600/(5 x 60 sec) meters/seconds.

I strongly suggest all newbies to go through the basic formulas before posting your doubts here. So, kindly go through the basic formulas for solving Time and Distance problems.

Have a nice day!

Shilpa said: (Sep 2, 2010)  
Hi Sundar,.

All these days I wat getting why we should multiply with 60.

Your explaination regarding that 60 is going to be useful for me. Your expalination was clean and clear.

Thank you so much.

Abdul Hafeez said: (Oct 11, 2010)  
Are engg entrance exam questions enough for clearing aptitude test?.

Jashwa said: (Dec 20, 2010)  
Why did you invert 5/18 into 18/5?

Jashwa-Marine said: (Dec 28, 2010)  
I didn't get why does change 5/18 into 18/5.

Jayan said: (Jan 5, 2011)  
I am very confused, How came 18?

Digant said: (Jan 6, 2011)  
Forget this above mentioned method

one man cover 600 m in 5 min thn in 60 min (1 hour)how much he cover

( 60 x 600 ) / 5 = 7200 m = 7200 / 1000 = 7.2 km / hour

1 km = 1000 m

Sundar said: (Jan 19, 2011)  
Thank you.

Deepa.Pk said: (Jan 28, 2011)  
@jayan,jashwa
to convert km/hr to m/sec, we hav to do in dis way.....
1km=1000m
1hr=3600sec
1km/hr=1000/3600 m/sec
therefore 1km/hr=5/18 m/sec


similarly to convert m/sec, we hav to in reverse way.....
1000m=1km ---> m=1/1000km
3600sec=1hr ---> sec=1/3600hr
its just a normal cross multiplication
m/sec=3600/1000 km/hr
therefore m/sec=18/5 km/hr

its not necessary to do al these steps. i included al the steps just for your better understanding......... hope u can understand now

thank u

Ravi S said: (Jan 29, 2011)  
Just formula s=d/t
=600/5*60m/sec

Sheela M B said: (Mar 28, 2011)  
To: Digant, Deepak. Pk, Sundar and Ravi S

Great guys. All of you have helped freshers in every best possible way to learn through... And freshers need not panic, go through all suggestions and sure you shall end up with happy results. & its an enlightning that you never forget your basics.

Gokul said: (Apr 13, 2011)  
s=d/t
=600/5*60
=600/300
=2m/s
1km=1000m
1/1000km=1m
3600s=1hr
1/3600=1s
2*3600/1000=7.2km/hr

Prajweetha said: (May 3, 2011)  
T=5 Min, 5*60=300sec
SPEED=DISTANCE/TIME
=600/300
=2m/s
convert m/s to km/sec by formula
2*18/5
=36/5
=7.2km/hr

Kavitha said: (May 4, 2011)  
Thank you sundar your explanation is realy good.

Sidd said: (May 9, 2011)  
For 600m 5 min. thn for
60min .... km
=> 600/5*60= 2m/sec
convert to km
so for 1 hr 3600sec
and 1000m = 1km
3600*2/1000=7.2km

Avinash said: (May 22, 2011)  
speed=distance/time

so the given distance is 600m and time is 5 mins..for this we have to convert minutes into seconds..5*60=300 seconds.

speed=(600*300)m/sec=2m/sec bt in answer they given in km/hr so we have to change m/sec in km/hr

speed=(2*18/5)km/hr=7.2 km

Yahiya said: (May 27, 2011)  
Yeah I understand the gokul explanation.

Abinaya said: (Jul 4, 2011)  
Thankyou prajweetha. Your explanation is really good.

Supriya said: (Jul 7, 2011)  
Thank you so much, you people have explained it well.

Vino said: (Sep 7, 2011)  
And onething before attempting the answers. We should study the formulas. Hence it is given in Important formulas. We must calculate using by mentioned formulas.

Vinoth said: (Sep 30, 2011)  
A person is running at a speed of 18km/hr After one min a bomb blasts . Sound travels at 330m/s. How long does the man run before he cud he hear the sound??

How to solve this question?

Seshu said: (Oct 5, 2011)  
In above problem clearly given that for 5 minutes travelled distance is 600 mtrs.multiplied with 12 on both sides then we get one hour travelled distance i.e. 12*5mnts is 12*600mts = 7.2 km.

Vijay said: (Oct 14, 2011)  
Please, dear. Not understand the conversion of the m/sec to km/sec. Please tell me brifely.

Ganesh said: (Mar 7, 2012)  
To convert km/hr to m/sec, we hav to do in dis way.....
1km=1000m
1hr=3600sec
1km/hr=1000/3600 m/sec
therefore 1km/hr=5/18 m/sec


Similarly to convert m/sec, we hav to in reverse way.....
1000m=1km ---> m=1/1000km
3600sec=1hr ---> sec=1/3600hr
its just a normal cross multiplication
m/sec=3600/1000 km/hr
therefore m/sec=18/5 km/hr

Riyazahmad said: (Mar 22, 2012)  
Its simple, no need to go through 18/5. do one thing,

1st convert m/s into km/hr i.e. (2m/s=2*3600/(1000)) after doing this calculation you will get {7.2 km/hr}

Ravichandran said: (Apr 20, 2012)  
600=5minutes therefore

120= 1 minute

60*120=7200 meters

Kilometer per hour = 7.2
Thats all

Priya said: (May 10, 2012)  
Why we convert 5 min into seconds?

Swayam said: (Jun 20, 2012)  
@Priya.

Our question is why we convert 5 min into seconds. Its because of the formula i.e. if speed of the body is 'a'm/sec then when we convert it into km/sec, it becomes (a*18/5) km/sec. In both cases time is required in sec. So it is necessary to convert 5 min into sec. Ok ?

Sandip said: (Aug 16, 2012)  
Simply,

One man cover 600 m in 5 minute
first calculation wht is dist cover for 1 minute
600mtr/5min = 120meter is cover per(1) minute
qus is find the km/perhour
1hour=60minute
120mtr*60minute = 7200meter is cover in 1hour(60minute)
find km
1000meter=1km
=7200/1000=7.2 km/perhour

Dinen said: (Sep 27, 2012)  
Very simple,

In 5 mins he covers 600 m.

In 1 min he will cover 600/5.

In 60 mins he will cover (600*60) /5 = 7200 m i.e. 7. 2 km.

Ravi Saini said: (Oct 18, 2012)  
In 1 km -1000 m
1 hr.-60 min.
1 min.-60 sec.

So, 1 hr.-3600 sec.
metre\hour to k.m\sec.

To do it, 3600.metr\1000.sec.
Now divide 3600 to 1000, we get 18\5.

Manoj said: (Dec 29, 2012)  
600 mtr in 5 minutes so
1 km = 1000 mtr

(600/5=120 mtrs per minute) so
1 hour = 60 minutes so
(60*120=7200 mtrs)

Here
(7200/1000)= 7.2 km/hr.

Sekhar said: (Jan 19, 2013)  
t=5 Mins, 5*60=300sec(1min=60 sec)
SPEED=DISTANCE/TIME
=600/300
=2m/s.

Convert m/s to km/sec by formula
2*18/5
=36/5
=7.2km/hr.

Rajwindr Singh said: (Apr 11, 2013)  
Answer: Option B.

Explanation:

Distance = 600 m.
Time = 5 min.

Speed = 600/5 = 120m/min or 120*60/1000 = 7.2km/hr.

Santhosh said: (Jul 5, 2013)  
2*60(min)*60(hr)/1000.

Then we get the answer 36/10(or)18/5*2.

Answer=7.2km/hr.

Indu said: (Aug 23, 2013)  
Speed = distance/time (or) m/sec.

1 min = 60 sec; 5 min = 5*60 sec = 300 sec.

Speed(x) = 600/300.

= 2m/sec.

x*(m/sec) = (x*18/5)km/hr.

= (2*18/5)km/hr.

= 36/5.

= 7.2.

Sandhyasasi said: (Sep 3, 2013)  
600/5*60 = 2 m/sec.

Converting to km/h,

= 2*18/5.

= 7.2 km/h.

Sameer Kashmiri said: (Jan 14, 2014)  
1st step:- change 600m into km.

600/1000 = 0.6.

2nd step:- change time 5 minutes into hrs.

5/60 = 0.0833.

You know,
speed = distance/time.

Now put the values,

Speed = 0.6/0.0833.

= 7.2.

Tejha said: (Jan 16, 2014)  
s = d/t.
s = 600m/5min.

120m/1min.

60*120/60*1.
7200m/60min .

7.2km/1hr.

Nimesh Kumar said: (May 26, 2014)  
Speed = Distance/Time.

Here Distance = 600 meters and Time = 5 mins.

Therefore, Speed = 600/5 meters/minutes.

We have to write it as in terms of meters/seconds. So we are multiplying it with 60 (1 min = 60 seconds).

So, Speed = 600/(5 x 60 sec) meters/seconds.

Sourav said: (Sep 13, 2014)  
Its just a one step answer. Just calculate how much he can travel in 60 minutes.

Arpita said: (Sep 23, 2014)  
How 18/5 come?

Help said: (Oct 2, 2014)  
I can understand how it came 5/18m/sec but can not understand 18/5 km/hr?

Sasi said: (Oct 30, 2014)  
We know that, 1 km = 1000 m and 1 hr = 3600 min i.e., 60 min*60 sec.

Like wise, 1 m = 0.001 km and 1 min = 0.00027777777 hr.

Which means, 1 m = 1/1000 = 0.001 km.

1 min = 1/3600=0.00027777777 hr.

So, km/hr = 0.001/0.00027777777 = 3.

6 which means 18/5.

That's why, for km/hr conversion we use 18/5.

Nvll said: (Nov 23, 2014)  
@Vinoth.

It doesn't actually matter he will be vaporized in a few ms so will never hear it.

I don't no one person who talks about m/second so why the need to convert to m/s anyway.

I came on to this site to find out what a wind speed of 2 m/s is, who talks about a wind speed of 2 m/s? 7.2 km/hr or 4 m/h or 3.8 knots I can work out, but 2m/s? Very geeky.

Siva said: (Dec 12, 2014)  
Where does 18 comes from?

Deba said: (Jan 10, 2015)  
= (1000/3600) = 5/18 m/sec.
1 km = 1000 m.
1 hr = 3600 sec.

Nik Edrus said: (Feb 23, 2015)  
How do you get 18/5?

Thirupathi said: (Feb 25, 2015)  
Given that,

Distance(d) = 600 m = 600/1000 km = 0.6 km.

Time(t) = 5 mns = 5/60 hrs = 1/12 hrs.

Now speed = distance/time = 0.6/(1/12) kmph = 0.6*12 = 7.2 kmph.

Advait Nandeshwar said: (May 3, 2015)  
Speed = 600 m/5 min.

= 600 m/5*60 sec.

= 600 m/300 sec.

= 2 m/s.

Therefore,

By applying formula.

x km/hr = 18/5 x m/s.

x km/hr = 18/5 x 2.

x km/hr = 36/5.

x km/hr = 7.2.

Sushil Pathak said: (Jul 11, 2015)  
Hi,

I know that I'm late. But I'm fresher.

Answer:

Option B.

Explanation:

Distance = 600 m.

Time = 5 min.

Speed = 600/5 = 120 m/min or 120*60/1000 = 7.2 km/hr.

Sumithra said: (Jul 31, 2015)  
Good. And why multiply 60 in 2?

Sagar said: (Aug 3, 2015)  
600/5 = 1000/60. Because we need answer in km/hr.

1km/1hr = 1000 mtrs/60 mins.

There fore cross cross multiplication of 600/5 = 1000/60.

You will get 36000/5000 = 7.2 is the answer. Any doubts?

Urbasi said: (Aug 6, 2015)  
Thank you so much to all of you. Your suggestion gives very simple and easy idea.

Priya said: (Aug 25, 2015)  
Why don't we use the no 12 or 16 instead of 18?

Firdosh said: (Oct 18, 2015)  
How get 5*60 = 2?

Anamika said: (Oct 21, 2015)  
What's that conversion formula come from the real real formula was 1000/(60*60)?

Rupamrd said: (Oct 25, 2015)  
In 5 minutes the person crosses 600 meter.

In 1 minute the person crosses 600/5 meter.

In 60 minutes the person crosses (600*60)/5 = 7200 meter = 7.2 km.

Deepa said: (Dec 20, 2015)  
I am very confused in step 2.

Pratik Dangol said: (Jan 5, 2016)  
In 5 mins 600 meter.

In 1 mins 600/5 = 120 meter.

In 60 mins (1hr) 120*60 meter = 7200 meter.

In 1 hr 7.2 km.

i.e 7.2 km/hr.

Jhanu said: (Feb 3, 2016)  
The speed is 600 m/5 min.

So, 5 min = 600 meters.

(1 hour = 12*5 min = 60 mins).

5min*12 = 600m*12.

60 minutes = 7200 meters.

So, 1 hour = 7000 m + 200 m.

1 hour = 7 km + 200 m.

= 7.2 km.

Saikiran said: (Feb 25, 2016)  
Is there any shortcuts for this problem?

Suriya said: (Feb 25, 2016)  
In step 2 how it came 18?

Raaj said: (Mar 4, 2016)  
Be cool for 5min 600m, so for 1 min 600/50 = 120m.

For 60min 60*120 = 7200m.

Liyaqat said: (Mar 7, 2016)  
1000m = 1 km.
600m = 600/1000 km = 0.6 km.

Time = 5 min.

5min=60/5 = 12h.
S=0.6 x 12 = 7.2.

Is my pattern is right or wrong. I got the answer. But I'm so confuse, I'm doing in a wrong manner but my answer is right that's strange. Please is there anyone to explain.

Liyaqat said: (Mar 7, 2016)  
@Suriya.

As we know 1km/hour=1000m / 60min x 60sec [bcoz 1km=1000m n 1h=60sec x 60min].

So 1 km/hour = 5/18 m/s.

Now listen if we convert km/h into m/s then we x 5/18.

If we convert m/s into km/h then we x 18/5. So 18 is there. Because we take a reciprocal during conversion of m to km.

Ahmad Sangrah said: (Apr 27, 2016)  
I'm confused with this type question, now I understand properly from your suggestions.

Thank you all.

Bdboy Hasan said: (May 2, 2016)  
In 5 minute he run 600 meter.
So, in 60 minute he run (600*60)/5 meter = 7200 meter.
So, speed is 7200/1000 = 7.2 kmph.

Note : We have to remember that we need to convert time in one hour and distance in km.

Naidu said: (May 16, 2016)  
The speed is 600 m/5 min.

So, 5 min = 600 meters.

(1 hour = 12 * 5 min = 60 mins).

5min * 12 = 600m * 12.
60 minutes = 7200 meters.

So, 1 hour = 7000 m + 200 m.
1 hour = 7 km + 200 m.
= 7.2 km.

Pankaj Kumar Verma said: (Jun 23, 2016)  
1 hour 12 m - 5 = 60 minute = 1 HOUR,

Than 600 m - 12 = 7200 m

Now convert km/hour,

Than required answer 7200/1000 = 7.2 km/hour.

Reehana said: (Jun 25, 2016)  
When we convert km/hr to m/s it's 18/5 and when we convert m/s to km/he it's 5/18.

Maureenash said: (Aug 13, 2016)  
Thanks for the clear and different solution.

Riyadhksd said: (Aug 17, 2016)  
I will explain you in a simple way.

Distance/time into 3.6,

So, 600/300 * 3.6 = 7.2,
3.6 = 3600/1000.

Sathiyaraj said: (Sep 19, 2016)  
Man crosses 600 meters in 5 minutes.

12 x 5 = 60 minutes => 1 hour,

So, 600 x 12 = 7200 meters/hr =>7.2 km/hr

Bukhari said: (Sep 30, 2016)  
It is very simple. If someone covers a distance of 600 meters in 5 minutes then in 1hour (60 minutes) he will cover a distance is,

600 metre = 5 minutes.
Multiplying with 12 both sides.
600 x 12 = 5 x 12,
7200 m = 60 minutes (1 hour),
7200/1000 m = 1 hour,
7.2 km in one hour.
So, speed is 7.2 km/hour.

Jjtt said: (Oct 11, 2016)  
Can someone explain where the 5 and 8 came from? I understand the formula but the 5 and 8 are throwing me off.

Kiranmaahi said: (Oct 19, 2016)  
@Digant.

Thank you so much I understood your explanation.

Minalo said: (Nov 3, 2016)  
@Digant. I don't get where you get 18 from? Please explain me.

Prince said: (Nov 20, 2016)  
@Minalo.

If you want to change in km then multiply the value with 18/5.

Mohite Kallappa said: (Nov 24, 2016)  
All values is used in above example.
S = d/t, ( 600/5 * 60) m/sec.

Then convert m/ sec into km/hr.

Suppoes,
km/hr = s.
1000/3600 = 2.
5/18 = 2.
= 2 * 18/5.
= 7.2 km/hr.

Rezuan said: (Dec 3, 2016)  
Distance = 600 m.
Time = 5 min = (5 * 60)s = 300 s.
Speed = ?
Speed = Distance/Time = 600m/300s = 2 m/s.

According to question we need to convert it m/s to km/hr.
m/sec=18/5 km/hr.

So, Speed = (2 * 18/5) km/hr.
Speed = 7.2 km/hr.

Samyuktha said: (Dec 26, 2016)  
Please make me understand this whole sum properly by anyone.

Jayalakshmi said: (Dec 28, 2016)  
Formula: speed = distance/time.

In question, given distance is in meter so convert the km and time given the minute so convert hours.

Sarah said: (Dec 30, 2016)  
Hi @Sundar.

Your explanation was really clear now I understand how this works thank you so much.

Shraddha said: (Jan 31, 2017)  
Hi @Sundar.

Your explanation is very nice. Can you tell me basic math's tricks like Percentage. How to calculate it is?

Khushi said: (Feb 8, 2017)  
@ Sundar.

Thank you so much, your explanation really helped me to pass my maths exam!

Amy said: (Feb 14, 2017)  
Here, the formula is either:

Sspeed= distance divided by time.
Time = distance divided by speed.
or
Distance = speed x time.

Sanskriti said: (Feb 24, 2017)  
The formula of converting into m/s an km/hr is;
m/s: XYZ multiplied by 18 by 5.

And

km/hr: XYZ multiplied by 5 by 18.

Arun Chauhan said: (Mar 16, 2017)  
@Sanskriti.

Please give me a suitable example to proved that?

K.P.M.Vasanth said: (Mar 28, 2017)  
Thank you for giving the explanation. Now I get the solution.

Gaurav Viradiya said: (Apr 10, 2017)  
600m convert to KM = 600/1000 = 0.6,
5min convert to Hrs. = 5/60 = 0.083,

Finally, 0.6/0.083 = 7.22.

Kishor Venkkat said: (May 9, 2017)  
Why do you convert to m/sec?

Praneel said: (Jun 6, 2017)  
@Kishor Venkkat.

It is based on m.k.s system of units.
m.k.s= metre.kilogram.second.

So, as given in minutes, we have to convert it into seconds.

Aayushi@Suri said: (Jun 10, 2017)  
Can anyone explain, What's wrong in below solution?

Step 1: 600m -> 600*18/5 =2160 km.
Step 2: 5 m -> 5/60 =0.083hr.

Result :
Speed = 2160 km/0.083 hr =26024 km/hr.

Where did I make a mistake? Please explain.

Manu said: (Jun 16, 2017)  
Step1: We are finding speed = distance/time.
Distance= 600mts,
Time = 5minutes, we are converting time is minutes into seconds so,
t = 5 * 60 = 300
Then, s =d/t=600/300= 2 mt per sec is comminng.
Now we r converting mt per sec to km per hour.
Then formula is x * 18/5,here x is s ,now 2*18/5=36/5=7.2km/hr .
Now speed =7.2km/hr.

Manu said: (Jun 17, 2017)  
Nice explanations, Thank you all.

Atul said: (Jul 1, 2017)  
600/5=120/min,
1min=120m,
60min=60*120m=7200,
1000m=1km.
So, 7200m/1000m=7.2/hr.

Dinesh said: (Jul 5, 2017)  
Here is a simple solution guys.

distance - 600,
mins - 5,
600/5 = 120 speed.
120 * 60 seconds = 7200 meters/1000 meters.
= 7.2 km Result.

Rika Raj said: (Jul 5, 2017)  
T=5/60hour,
D=600/1000Km=3/5Km,
Speed=Distance /Time=3/5*60/5=7.2Km/hr.

Janne said: (Jul 13, 2017)  
Hi guys. I'm still confused. How did you compute 60x5/18 manually? How did you get the answer 50/8? Explain in detail.

Priya said: (Jul 18, 2017)  
How it is coming 18÷5? Please explain it.

Stevie Dee said: (Aug 15, 2017)  
Hey, guys, The sum is relatively easy if you know how and while there are some good examples above, it can be broken down even further in the order you can understand it better, especially when it comes to 18/5 part of the formula. So let's break it down (sorry for the long explanation and simple steps).

PART 1

1. Divide the Distance by the time: 600m / 5min = 120m/min.
2. Divide the new Distance (120m/min) by 60 (the number of seconds in a minute) to give you the distance travelled per second: 120m/min / 60 = 2m/sec.

PART 2

We have established that we are travelling at 2m/sec (write that down and leave it for now, we will come back to this later). Now we need to breakdown 1Km into meters (1000m) and 1hour into seconds in order to change from meters per second to Kilometres per hour.

1. 1 Kilometre in length is 1000m (simple)
2. Next work out how many seconds are in 1 hour of time. There are 60min in an hour and 60 seconds in each minute, therefore to get the total seconds we must Multiply 60min with 60 Seconds: 60min x 60Sec = 3600Sec in 1hr of time.
3. This now leaves us with 3600/1000. At this point we can complete the question and there is no real need to break it down further, please follow the example: 2m/sec x 3600sec / 1000m = 7.2Kph

4, However, for those of you still wondering where they got 18/5 from, the above numbers can be broken down further to make it easier to work with if you are not using with a calculator etc. if you were to remove the zeros from 3600/1000 you are left with 36/10 and if you were to half these numbers again you will come to 18/5 (and so on). You can apply both these number to the same sum and the results will be the same, you have just made it easier to calculate:

Answer 1:
600 / 5 = 120 / 60 = 2m/sec
1km = 1000m
1hr: 60 x 60 = 3600sec
2 x 3600 / 1000 =7.2

Answer 2:
600 / 5 = 120 / 60 = 2m/sec
1km = 1000m
1hr: 60 x 60 = 3600sec
36/10
2 x 36/10 = 7.2

Answer 3:
600 / 5 = 120 / 60 = 2m/sec
1km = 1000m
1hr: 60 x 60 = 3600sec
36/10
18/5
2 x 18/5 =7.2

I hope this helped?

Md. Jahir Uddin said: (Aug 29, 2017)  
Very nice solution. Thanks.

Mr.Nithin said: (Sep 7, 2017)  
Thank you guys for the explanation.

Awanish Mishra said: (Sep 23, 2017)  
We know that s=d/t,
d=600m and t=5m,
we know that,
1min.=60sec,
therefore, 5min=5*60=300sec,
600/300,
= 2.

2 * 18/5 = 7.2m/m.

A.S.Raja said: (Oct 21, 2017)  
Thanks for the explanation friends.

Shanmuga Raja said: (Oct 21, 2017)  
We know that speed=(distance / time).
so speed=(600/300)=2m/s.
2m/s= 2(18/5)=7.2km/hr.

Anmol said: (Dec 7, 2017)  
Hi everyone,

Speed = Distance/Speed
Time= Distance/Speed
Distance=Speed x Time

1km=1000m,and 1hr=3600seconds
Therefore, 1km/hr=1000m/3600sec =5m/18sec=5/18m/s.

Therefore,
to change a speed in km/hr to a speed in m/sec, multiply by5/18.
Conversely, to change a speed in m/sec to a speed in km/hr, multiply by 18/5.

Aadarsh Kumar said: (Jan 10, 2018)  
Distance= 600 metres.
Time= 5min
Speed =?
Speed = distance/time.
Speed = 600/5=120 m/sec.
Because,
1min=60min
120 min= 120*60 min= 7200 min.
Because,
1 km = 1000 metre.
7200 metre / 1000 metre =7.2 km/hr prove that.

Raj Tiwari said: (Jan 23, 2018)  
Use simple logic.

Just one thing is there, basic.
Speed is distance/time.


Since distance is 600m so its 0.6km.
Time is 5 min, so its 5/60, 1/12.

Now, speed= distance/time
speed = 0.6/1by12
hence speed = 0.6*12
think as 10x6 is 60 plus 2 x 6 12.
so 60+12 72.
7.2 answer.

Sowgandhika said: (Jan 24, 2018)  
1km=1000meters.
l hr=3600 sec.
So, the speed =distence/time.
If we simplify
1000/3600=5/18 m/s we get.
converting m/s to km/hr ,

m/s = (1/1000)*3600=18/5 km/hr. We get in the given problem, the speed is converting ms to km is,
2*18/5=7.2 km/hr we get.

Ramya said: (Feb 9, 2018)  
Thank you all for explaining it.

Pranathi said: (Apr 6, 2018)  
@Shikha.

1m/s=18/5km/h.

Rajkumar said: (May 16, 2018)  
1Meter/minute=0.06km/hr.

Speed=600/5 meter/minute.
Speed=120.
120 meter/minute=120*0.06 km/hr
=7.2km/hr.

120 meter/minute=120*0.06 km/hr
=7.2 km/hr.

Dorothyeva said: (Jul 5, 2018)  
I do not understand where 18 came from? Please Explain me.

Prabakaran said: (Jul 18, 2018)  
The speed formula= distance/time.

So we have speed=600 metres/ 5 min
In this 5 is a minute value so we have to convert it into seconds
Because metres/seconds is a current formula
so we need to change the 5 min value into seconds
1 min= 60 seconds.
So 5 min = 5*60.
= 300 sec that's why 60 will come in this section
now we calculate speed = 600/300 m/sec.
= 2 m/sec

On step 2:
we need the man speed in km/hour.
so we need to convert m/sec into km/hour.
using 1000/3600= 5/18.
Because 1 km= 1000 m.
and 1 hour= 3600 sec ( 1min= 60 sec then 1hour= 60 min so 60*60= 3600 sec)
the answer is 2*5/18= 7.2 km/hour.

Shivani said: (Aug 9, 2018)  
@Dorothyeva.

Speed = distance /time.
D=600 m,
T=5 minutes,
T=5*60 sec,
Now put into formula.

Speed= 600/300 (m/s).
But we are required to find it in km/hr.
Km/hr......> m/s. (Multiply it by 5/18).
m/s..........> km/hr. (Multiply it by 18/5).
S =(600/300) * 18/5.
S=36/5.
Speed = 7.2 km/hr.

Khushboo Rahman said: (Sep 1, 2018)  
Easy way to solve this problem.

Speed=Distance/Time.
Now,
1km=1000m,
1/1000km=1m,
600/1000km=600m,
i.e. 0.6km=600m,
1hr=60min,
1/60hr=1min,
5/60hr=5min, i.e. 0.083hr=5min.

speed=distance/time.
=(600/5)m/sec.
=(0.6/0.083)km/hr.
speed=7.22km/hr.

Priya said: (Sep 19, 2018)  
Speed = dis/time so speed = 600/5 convert it directly to km/hr (1 km= 1000m and1 hour = 60 minutes).

So, speed = 600*60/5*1000 = 7.2km/hr.

Reddy said: (Sep 30, 2018)  
Thanks, @Priya.

Your explanation simple and good.

Prakash said: (Dec 6, 2018)  
= D/t
= 600/5 * 60 * 18/5,
= 7.2.

Snehql said: (Jan 27, 2019)  
Can anyone please help me for solving this question?

A boat goes 8 km downstream in 40 min and returns to the same point in 1 hr how much time will it take to cover a distance of 144 km in still water?

Chandru said: (Apr 7, 2019)  
@Snehql.

It took 15 hrs.

Milesh Bariya said: (Jun 24, 2019)  
Simply,

(2/1000) = 0.002km/sec
Then (0.002*3600) = 7.2km/sec.

Note: small quantity to big quantity then divide i.e; 2/1000 = meter into kms.

Ronak said: (Jul 11, 2019)  
How to calculate 2 * 18/5? Please explain in detail.

Tobzs said: (Jul 16, 2019)  
We can directly divide 60/5 and multiply with 600 and divide it with 1000.
60/5*600/100 = 7.2.

Sidh said: (Nov 27, 2019)  
Explain in a simple way.

Pallavi said: (Dec 20, 2019)  
Formula(x*18/5)km/hr.

Akash said: (Dec 30, 2019)  
Simple(no formulas).
600m/5 min = 120m per 1min.
1hr = 60min.
120x60 = 7200m .
7200m = 7.20km/hr.

Sanju said: (Mar 30, 2020)  
How it is 7.2 km/her?

Anyone explain that.

Vishwa said: (May 3, 2020)  
@Sanju,

They said that 600m covered in 5 mins,
How much will he cover in 1hour? right.
just cal. it as
1hr= 60mins right,
Given in 5mins=600m then,
in 60mins=?

Calculate and find out one min distance that is 600/5=120m per min he travels.
So then for 60mins=60*120=7200m i.e, 7.2km.

Mao said: (May 10, 2020)  
The answer is 7.2. Agree with the given answer.

Adrija Das said: (Jul 23, 2020)  
Why divided by 60?

If we want to convert minute to seconds then don't we have to multiply the minute * 60? Please anyone explain.

Pio Myria said: (Jan 20, 2021)  
Step-1: We that distance =600m,time is 5min.
Step-2: Formula=speed=distance/time,
600m/5* 60 = 2m/s.

Step -3 : convert m/s to km/hr.
2*18/5=7.2km/hr ans.

Yashwanth Reddy Chamala said: (Feb 26, 2021)  
Street lenght= 600m.
Time is taken by the person to Cross the street= 5min,
600m/5min*(3/50)=7.2km/hr,
Speed of the person in km=7.2km/hr.
1m/min=3/50km/hr.

Minnal said: (Jun 11, 2021)  
Street lenght = 600m.
Time is taken by the person to Cross the street = 5min,
600m/5min *(3/50) = 7.2km/hr,
Speed of the person in km =7.2km/hr.
1m/min = 3/50km/hr.

Priya said: (Jul 6, 2021)  
We know that speed= distance/time.

But we can't find the speed for m/min.
So, we can first convert 5 mins to sec. 5*60 = 300 s.
Now we need to find the speed= distance/time= 600/300= 2 m/s.

But we need km/hour. so for converting m/s to km/hour we need to multiply the speed(in m/s) * 18/5 (5/18 for km/hour into m/s).
So, 2*18/5=36/5= 7.2.

Umang Joshi said: (Aug 11, 2021)  
Speed = distance*time guys now,
Speed = 5min OR 5*60= 300 second
Distance = 600m.

By using above formula;
s = D/T.
S = 600/5 * 60.
= 2m/sec.

Converting it into km/h to m/sec we do 5/18 which is 1000/3600,
For converting m/s into km/hour use 18/5 -----> (1)
Now using (1).

18/5*2 = 7.2 km/hour answer which is option (B)
hope you all got it.

Faria said: (Aug 28, 2021)  
1000m = 1 km.
So, 1 m =( 1/1000) km,
600 m = 600/1000, i.e 0.6 km,
In 5 minutes a person passes 0.6km,
In 1 minute a person passes 0.6/5,
In 60 minutes a person passes (0.6x60)/5, i.e 7.2 km.

Ans : 7.2 km.

Akuymakan said: (Sep 13, 2021)  
I don't get it. Please explain in detail.

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