# Time and Distance - Aptitude Questions and Answers - RejinpaulPlacement

15.
An athlete runs 200 metres race in 24 seconds. His speed is: [S.S.C. 2002]

Solution:   Speed = 200/24 m/sec = 25/3 m/sec
= [(25/3) * (18/5)] km/hr = 30 km/hr
16.
A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour? [R.R.B. 2003]

Solution:   Speed = 600 / (5 * 60) m/sec = 2 m/sec
= [2 * (18/5)] km/hr
= 7.2 km/hr
17.
A man walking at the rate of 5 km/hr crosses a bridge in 15 minutes. The length of the bridge (in metres) is : [S.S.C. 2000]

Solution:   Speed = [5 * (5/18)] m/sec = 25/18 m/sec
Distance covered in 15 minutes = [(25/18) * 15 * 60] m = 1250 m.
18.
How long will a boy take to run round a square field of side 35 metres, if he runs at the rate of 9 km/hr? [S.S.C. 1999]

Solution:   Speed = 9 km/hr
= [9 * (5/18)] m/sec = 5/2 m/sec.

Distance = (35 * 4) m = 140 m.

Time taken = [140 * (2/5)] sec = 56 sec.
19.
A car is running at a speed of 108 kmph. What distance will it cover in 15 seconds? [R.B.I. 2003]

Solution:   Speed = 108 kmph
= [108 * (5/18)] m/sec = 30 m/sec

Distance covered in 15 sec = (30 * 15) m = 450 m.
20.
One of the two buses complete a journey of 300 km in 7   1/2 hours and the other a journey of 450 km in 9 hours. The ratio of their average speeds is: [R.R.B. 2001]