Question: Two, trains, one from Sylhet to Dhaka and the other from Dhaka to Sylhet, start simultaneously. After they meet, the trains reach their destinations after 16 hours and 25 hours respectively. The ratio of their speeds is-
Solution: 
let, they meet at X, and Train A and B have the speed of p and y respectively.
in the time of t,
A covers = pt distance
B covers = qt distance
after meeting at X point,
A covers the rest part in 16 hours and B in 25 hours.
so,
distance covered by A is = 16p
distance covered by B is = 25q
∴ pt = 25q......(i)
and, qt = 16p.......(ii)
from equations (i) and (ii) we we get,
p/q = 25q/16p
p
2/q
2 = 25/16
p/q = 5/4
p : q = 5 : 4