The speed of the boat in still water is 20 km/hrs and speed of the stream is 5 km/hr. Find the time taken to travel 50 km downstream and 30 km upstream by the boat.

A boy is running at a speed of p km/hr to cover a distance of 1 km. But, due to the slippery ground, his speed is reduced by q km/hr (p>q). If he takes r hours to cover the distance, then

A 132 meter long train passes an electric pole in 6 second. The speed of a train is?

Car A travels at the speed of 65 km/hr and reaches its destination in 8 hours. Car B travels at the speed of 70 km/hr and reaches its destination in 4 hours. What is the ratio of the distance covered by car A and car B respectively?

Two men P and Q start together from place A at 3 km/h and 3.75 km/h respectively for place B. Q reaches half an hour before P. What is the distance that each one has covered ?

Piyush covers a certain distance on bike. Had he moved 3 km/h faster, he would have taken 20 min less. If he had moved 2 km/h slower, he would have taken 20 min more. The distance covered (in km) is:

Viraj swims for $12\frac{1}{2}$ hours while going 24 km down stream and 36 km upstream. But he takes just 12 hours to swim 36 km down steam and 24 km up stream. At what rate is the river flowing ?