3. Train P overtakes train Q double its length and traveling at half of speed of train P in 36 seconds. Train P crosses train R going in the opposite direction at double its speed in 8 seconds. If the speed of train P is 72 km/ph then the length of train R is?

A. 330 m B. 360 m C. 390 m D. 420 m

Answer Answer: Option B Explanation: For Train P
length = L, Speed = 72 kmph
For train Q
length = 2L, Speed = 36 kmph
(L + 2L)/(72 - 36)X5/18
L= 120 meter
For train R
Speed = 2 X 72 = 144 kmph
& length = x meter
(120 + x) / (144 + 72)X5/18 = 8
x = 360 meter

4. Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr.The faster train passes the slower train in 36 seconds. The length of each train is?

A. 50 m B. 72 m C. 80 m D. 82 m

Answer Answer: Option A Explanation: Let the length of each of train be X meters, Then distance covered = 2x meters.
Relative speed = (46-36) km /hr = ( 10*5/18) m/sec = (25/9) m/sec
2x/36= 25/9 = 2x =100 = x= 50

5. A train takes 18 seconds to pass completely through a station 162 meter long and 15 seconds through another station 120 m long.The length of the train is?

A. 70m B. 80m C. 90m D. 100m

Answer Answer: Option C Explanation: Let the length of the train be x meters
x+162/18 = x+120/15 =15(x+162) = 18(x+120) = x= 90 m