Answer: 10 a.m

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.
20x + 25(x - 1) = 110
45x = 135
x = 3.
So, they meet at 10 a.m.

Answer: 50 m

Explanation:

Answer: 30

Explanation:

Answer: 350 m

Explanation:

Answer: 50 m

Explanation:

Answer: 40 sec

Explanation:
Formula for converting from km/hr to m/s: X km/hr = X x (5/18) m/s.
Therefore, Speed = 45 x (5/18) m/sec = 25/2 m/sec.
Total distance to be covered = (360 + 140) m = 500 m.
Formula for finding Time = Distance / Speed
Required time = (500 x 2 sec)/25 = 40 sec.

Answer: 12 min

Explanation:
in one hour the train covers 50 km at 50 kmph, 40 km at 40 kmph
=> The difference in distance covered = 10 km
=> It would have covered this distance in 10/50 = 0.2 hours = 12 minutes
It stops for 12 minutes in an hour

Answer: 2:1

Explanation:
S1/S2 = √t1 / √t2
=> S1/S2 = √20 / √5 = √4 / 1
=> 2/1
One train travels twice as fast as the other

Answer: ] 258 m, 12 6/7 secs

Explanation:
the length of the faster train b l m.
=> The two trains move at a relative speed of (72 – 54) = 18 kmph
=>(192 + l) / [(1000)(18)] = 1.5/60 = l = 258 m
=>If the trains move in opposite directions they approach each other at a relative speed of (72 + 54) = 126 kmph
=>The time taken to pass completely (192 + 258) / [(1000)(126)]3600
= 12 6/7 sec

Answer: 3 minutes

Explanation:
length of the train = 24(60) + 60 = 1500 m.
=> Total distance to be covered = 1.5 + 1.5 = 3km
=> Time taken = 3/60 = (3/60)60 = 3 minutes