Question: 6 -

A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform? 

200 m

180 m

320 m

240 m

Answer:

240 m

Solution:

Speed = [54 * 5/18] m/sec = 15 m/sec.

Length of the train = (15 * 20) m = 300 m. 

Let the length of the platform be x meters. 

Then, x + 300 / 36 = 15

x + 300 = 540

x = 240 m. 

Question: 7 -

A train 110 meters long is running with a speed of 60 kmph. In what time will it pass a man who is running at 6 kmph in the direction opposite to that in which the train is going?

5

6

9

4

Answer:

5

Solution:

Speed of train relative to man = (60 + 6) km/hr = 66 km/hr

[66 * 5/18] m/sec = [55/3] m/sec. 

Time taken to pass the man = [110 * 3/55] sec = 6 sec

Question: 8 -

A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform? 

240 m

None of these

120 m

300 m

Answer:

240 m

Solution:

Speed = (54 * 5/18) m/sec = 15 m/sec. Length of the train = (15 x 20)m = 300 m. Let the length of the platform be x meters. Then, (x + 300)/36 = 15 ==> x + 300 = 540 ==> x = 240 m.

Question: 9 -

A 300 meter long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform? 

200 m

150 m

350 m

400 m

Answer:

350 m

Solution:

Speed = [300 / 18] m/sec = 50/3 m/sec.

Let the length of the platform be x meters.

Then, x + 300 / 39 = 50/3 

3(x + 300) = 1950 ¨ x = 350m.

Question: 10 -

The length of a train and that of a platform are equal. If with a speed of 90 k/hr, the train crosses the platform in one minute, then the length of the train (in meters) is: 

650

750

850

550

Answer:

750

Solution:

Speed = [90 * 5/18] m/sec = 25 m/sec; Time = 1 min. = 60 sec.

Let the length of the train and that of the platform be x meters.

Then, 2x/60 = 25 ¨ x = 25 * 60 / 2 = 750