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:
215 comments Page 18 of 22.

RAJWINDR SINGH said:   1 decade ago
Answer: Option B.

Explanation:

Distance = 600 m.
Time = 5 min.

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

Sekhar said:   1 decade ago
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.

Manoj said:   1 decade ago
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.

Ravi saini said:   1 decade ago
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.

Dinen said:   1 decade ago
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.

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

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 ?

Priya said:   1 decade ago
Why we convert 5 min into seconds?

Ravichandran said:   1 decade ago
600=5minutes therefore

120= 1 minute

60*120=7200 meters

Kilometer per hour = 7.2
Thats all

Riyazahmad said:   1 decade ago
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}


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