Aptitude - Time and Distance - Discussion

Speed = dis/time.
Dis = 600.
Speed = (600÷5*60) = 2m/sec.
We need speed km/hr 18/5.
2*18÷5 = 7.2km/hr.

Your Explanation is better than others. Thanks @Lavanya.

Guy's those who don't know how 18 comes.

Here is the answer 3.6 multiply 5=18?

Thank you all for giving a great explanation.

Speed = Distance/Time.

Distance = 600 m = 600 *18/5 = 2160,
(We have to multiply distance * 18/5 to convert m to km)

Time = 5 mins = 5/60hrs,
(We have to divide mins by 60 to convert it to hr).

Now, Speed = 2160/5/60 = 2160/5(1/60) = 7.2,
Hope you understood now.

Thanks for the explanation @Lavanya.

From where you got 18, I don't understand.

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!

@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

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.