If the speed of a boat in still water is 20 km/hr and the speed of the current is 5km / hr, then the time taken by the boat to travel 100km with the current is

Speed of a along and against the current are 14 km / hr and 8 kms/hr respectively. The speed of the current is:

The water in a river is flowing at the rate of 4 km/hr. If the width and depth of the river is 8m and 4m respectively, then how much water will enter the sea in 15 minutes.

A work could be completed in 100 days by some workers. How- ever, due to the absence of 10 workers, it was completed in 110 days. The original number of workers was:

In a one kilometre race A, B and C are the three participants. A can give B a start of 50m. and Ca start of 69 m. The start, which B can allow C is

In an examination, 40% of the candidates write their answers in Urdu and the rest in Marathi. The average marks of the candidates writing in Urdu is 74 and the average marks of the candidates writing in Marathi is 77. What are the average marks of all the candidates? 

A boat travel 240 km downstream in 3 hours and the time is taken by the boat to travel the same distance in upstream in 6 hours. Find the speed of stream (in kmph).

The average age of Ram and his son is 48 years. The ratio of their ages 13 years ago was 11 : 3. What is the present age of son?