Speed = Distance⁄Time Time = Distance⁄Speed P km/hr = (P x 5⁄18)m/sec P m/sec = (P x 18⁄5)km/hr
If the ratio of the speeds of P and Q is p:q, then the ratio of the times taken by them to cover the same distance is
1⁄p:1⁄q or q : p
The average speed of the journey is
(2pq⁄p+q)km/hr
if a man covers a certain distance at p km/hr and an equal distance at q km/hr