1. Busses start from a bus terminal with a speed of 20 km/hr at intervals of 10 minutes. What is the speed of a man coming from the opposite direction towards the bus terminal if he meets the buses at intervals of 8 minutes?

1. 3 km/hr

2. 4 km/hr

3. 5 km/hr

4. 7 km/hr

5. None of these

Answer & Explanation

Answer:- 3

Explanation :-

Distance between the buses = 20*(60/10) km

Let the speed of the man be x km/h

For the man, 103km is covered in 8 minutes with a relative speed of km/hr

speed of the man = 5 kmph

Distance covered in 10 minutes at 20 km/h = Distance covered in 8 minutes at (20 + x) km

20*10/60 = (20 + x) * 8/60

200 = 160 + 8x

x = 5 km/h

2. The distance between two cities A and B is 330km. A train starts from A at 8 (a)m. and travels towards B at 60 km/hr. Another train starts from B at 9 (a)m. and travels towards A at 75 km/hr. At what time do they meet?

1. 10 am.

2. 10 : 30 am.

3. 11 am.

4. 11 : 30 am.

5. None of these

Answer & Explanation

Answer:- 3

Explanation :-

Distance covered by first train in 1 hr = 60 km

Therefore , Distance covered by two trains at 9 A.M. = 330 – 60 = 270 km

Relative speed = 60 + 70 = 135 km/h

Time of meeting of Both the trains = 270/135 = 2 hrs

Therefore, Both trains meet at = 9 + 2 = 11 A.M.

3. Two trains are moving on two parallel tracks but in opposite directions. A person sitting in the train moving at the speed of 80 km/hr passes the second train in 18 seconds. If the length of the second train is 1000 m, its speed is?

1. 100 km/hr

2. 120 km/hr

3. 140 km/hr

4. 150 km/hr

5. None of these

Answer & Explanation

Answer:- 2

Explanation :-

Let the speed of the second train be x km/h

Man’s speed = 80 km/h = 80 *5/18

According to question

1000/(x + (80*5)/18) = 18

1000 = 18x + 400

x = 600/18 m/s = (600/18)* (18/5) = 120 km/h

4. In covering a distance of 30 km, Abhay takes 2 hours more than Sameer. If Abhay doubles his speed, then he would take 1 hour less than Sameer. Abhay’s speed is?

1. 5 kmph

2. 6 kmph

3. 6.25 kmph

4. 7.5 kmph

5. None of these

Answer & Explanation

Answer:- 1

Explanation :-

Let Abhay’s speed = x km/h

Time = Distance / Speed

(30/x) – (30/2x) = 3

6x = 30

x = 5 km/h