11.

Two stations A and B are 110 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?

A. 9 a.m. B. 10 a.m.
C. 10.30 a.m. D. 11 a.m.
Answer and Explanation
Answer:B
Explanation: Suppose they meet x hours after 7 a.m. Distance covered by A in x hours = 20x km. Distance covered by B in (x - 1) hours = 25(x - 1) km. Therefore 20x + 25(x - 1) = 110 => 45x = 135 => x = 3. So, they meet at 10 a.m.
12.

Two trains 200 m and 150 m long are running on parallel rails at the rate of 40 kmph and 45 kmph respectively. In how much time will they cross each other, if they are running in the same direction ?
A. 72 sec B. 132 sec
C. 192 sec D. 252 sec
Answer and Explanation
Answer:D
Explanation: Relative Speed = (45 - 40 ) Kmph = 5 kmph =(5 x 5 / 18)m/sec = (25 / 18 ) m/sec Time taken = (350 x 18 / 25) sec = 252 sec.
13.

Two, trains, one from Howrah to Delhi and the other from Delhi to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is:

A. 2 : 3 B. 4 : 3
C. 6 : 7 D. 9 : 16
Answer and Explanation
Answer:B
Explanation: Let us name the trains as A and B. Then, (A's speed) : (B's speed) = √b : √a = √16 :√ 9 = 4 : 3.
14.

A train 110 m long passes a man, running at 6 kmph in the direction opposite to that of the train, in 6 seconds The speed of the train is ?
A. 54 km/hr B. 60 km/hr
C. 66 km/hr D. 72 km/hr
Answer and Explanation
Answer:B
Explanation: Speed of the train relative to man =(110 / 6 ) m/sec = (110 / 6 x 18 /5) km/hr = 66 km/hr Speed of the train be x kmph Relative Speed =(x + 6 ) kmph. = x + 6 = 66 x = 60.
15.

A 400m long train is running at 72 Kmph. how much time it will take to cross an electric pole?
A. 15sec B. 20sec
C. 19sec D. 21sec
Answer and Explanation
Answer:B
Explanation: Formula: Distance = Speed * Time If we convert Kmph in to Mpsec multiply by 5/18, 400 = 72 KmpH * time 400 = 72*5/18 * time Time = 20Sec