1. A boat covers 24 km upstream and 36 km downstream in 6 hours while it covers 36 km upstream and 24 km downstream in 6 hours. The velocity of the current is :

2. A man can row downstream at 14 km/hr and upstream at 9 km/hr. Man?s rate in still water is :

3. A boat goes 40 km upstream in 8 hours and 36 km downstream in 6 hours. The speed of the boat in standing water is :