Aptitude - Time and Distance - Discussion

Discussion Forum : Time and Distance - General Questions (Q.No. 1)
1.
A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?
3.6
7.2
8.4
10
Answer: Option
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.

Discussion:
182 comments Page 2 of 19.

Dewesh Mishra said:   1 year ago
Distance = 600 m = 0.6 km (since 1 km = 1000 m).
Time = 5 minutes = 5/60 hours (since 1 hour = 60 minutes).

Now we can use the formula:

Speed = Distance/Time.
Speed = 0.6 km / (5/60) hours
Speed = 0.6 km / 0.08333 hours.
Speed = 7.2 km/h

Therefore, the person's speed is 7.2 km/h (kilometres per hour).
(18)

Sasi said:   9 years ago
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.

Shivani said:   6 years ago
@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.

Bukhari said:   8 years ago
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.

Sheela M B said:   1 decade ago
To: Digant, Deepak. Pk, Sundar and Ravi S

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Liyaqat said:   8 years ago
@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.

Vishwa said:   4 years ago
@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.

Sandip said:   1 decade ago
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

Khushboo Rahman said:   6 years ago
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.

Swayam said:   1 decade ago
@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 ?


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