A tap is filling a 10-liters tank at the speed of 5 liters per minute.

A hole locates at the bottom of the tank which leaks water at

the speed of 1 liter per minute. It takes - minutes to fill the

tank.

It takes 2.5 minutes to fill the tank.

Explanation:

The net speed or net rate for filling the 10-liters tank is equal to the speed the tap is filling less the speed the water is leaking through the hole located at the bottom of the tank:

Net rate = rate of filling - rate of leaking Net rate = 5 liters/minute - 1 liter/minute Net rate = 4 liters/minute

Thus, consiedering the tank is empty at the beginning, the time is:

Time = Volume of the tank / net rate of filling Time = 10 liters / (4liters/minute) Time = 2.5 minutes ← answer