- Two trains running in opposite directions cross a man standing on the platform in 21 seconds and 15 seconds respectively and they cross each other in 19 seconds. The ratio of their speeds is
Let the speeds of the two trains be x m/sec and y m/sec respectively.
length of the first train = 21x
length of the second train = 15y
(21x+15y)/(x+y) = 19
- The distance travelled by a train is 1830km. The speed of the train is one more then twice the time taken to travel the distance. What will be the respective ratio of the time taken and speed of the train?
Let the time taken to cover the distance=t
t(2t+1) = 1830
Ratio =30: (2*30+1)= 30:61.
- Two trains 150 m and 210 m long run at the speed of 68 km/hr and 76 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is
Travel in opposite direction speed=76+68=144km/hr.
Time to cross each other= 360/144*5/18
=(360*18) / (144*5)
- A train passes a station platform in 26 seconds and a man standing on the platform in 15 seconds. If the speed of the train is 72 km/hr, what is the length of the platform?
Length of the train =72*5/18*15=300m.
Length of the platform be x
- Two trains, one from A to B and the other from B to A, start simultaneously. After they meet, the trains reach their destinations after 16 hours and 25 hours respectively. The ratio of their speeds is:
(A’s speed) : (B’s speed) = √b : √a = √25 : √16 = 5 : 4.
- Two trains of equal length are running on parallel lines in the same direction at 45 km/hr and 32 km/hr. The faster train passes the slower train in 48 seconds. The length of each train is
Let the length of the train be x.
Running in same direction then Speed =45-32=15km/hr.
- Two trains are running at 45 km/hr and 30 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 6 seconds. What is the length of the fast train?
Train travelling in same direction speed=45-30=15km/hr
Length of faster train= 15*5/18*6
- Two trains, each 150 m long, moving in opposite directions, cross each other in 10 seconds. If one is moving twice as fast the other, then the speed of the slower train is
Let the speed of the slower train =x km/hr and
Length of the faster train=2x km/hr.
- 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?
If 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.
They meet at 10am.
- A 300 metre long train crosses a platform in 39 seconds while it crosses a post in 18seconds. What is the length of the platform?
Let the length of the platform be x.