Time & Distance (11)

1. A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?
1. 8.2
2. 4.2
3. 6.1
4. 7.2

Explanation :-

Distance = 600 m = 600/1000 = 6/10 km
Time = 5 minutes = 5/60 = 1/12
Speed = (6/10) / (1/12) = 7.2 km/h

2. Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?
1. 12
2. 11
3. 10
4. 9

Explanation :-

In 1 Hour , Distance covered because of stoppages = 54 – 45 = 9 km
Time = Distance / Speed
Time taken to cover 9 km = (9/54) hour = (1/6)*60 minutes = 10 minutes

3. A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.
1. 121 km
2. 242 km
3. 224 km
4. 112 km

Explanation :-

Let time taken to cover 1st half = x hr
Therefore ,  time taken to cover 2nd half = (10 – x) hr
istance = Time*Speed
Distance covered in 1st half = 21x [because,] Distance covered in 2nd second half = 24(10 – x)
21x = 24(10 – x)
=> 45x = 240
=> x = 16/3
Total Distance = 2*21(16/3) = 224 Km

4. A car traveling with 5/7 of its actual speed covers 42 km in 1 hr 40 min 48 sec. What is the actual speed of the car?
1. 30 km/hr
2. 35 km/hr
3. 25 km/hr
4. 40 km/hr

Explanation :-

Distance = 42*1000 = 42000 m
Time = 1 hr 40 min 48 sec = 3600 + (40*60) +48 sec = 6048 sec
Speed = (42000/6048) m/s = (42000/6048) * (18/5) =25 × 7/5 = 35 km/h

5. A man covered a certain distance at some speed. If he had moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. What is the the distance in km?
1. 36
2. 38
3. 40
4. 42