Find the mean of first Five Prime Numbers.

The average age of 12 players of a team is 25 years. If the captain's age is included, the average age increases by 1 year. The age of the captain is: 

A man can row 30 km downstream and return in a total of 8 hours. If the speed of the boat in still water is four times the speed of the current, then the speed of the current is: 

If 10 men or 20 boys can make 260 mats in 20 days, then how many mats will be made by 8 men and 4 boys in 20 days? 

A, B and C enter into a partnership. A invests Rs. 8000 for the whole year, B puts in Rs. 12000 at the first and increasing to Rs. 16000 at the end of 4 months, whilst C puts in at first Rs. 16000 but withdraw Rs. 4000 at the end of 9 months. Find the profit of A at the end of year, if the total profit is Rs. 22600.