An underground water supply has a depth of 200 m of water. Water seeps in at the rate of 4 cm / year . Water is pumped out at the rate of 1m / year . How long will this water supply last? To find the net water loss from an underground water supply, subtract the amount that seeps into the water sup ply from the amount removed from the water supply. How long will the water supply last if water seeps in at the rate of 10 cm / year and is removed at the rate of 10 cm / year ?

208 years.

Explanation:

The water supply last for 208 years if the water seeps in at the rate of 4 cm / year  and water is pumped out at the rate of 1m / year. The water supply last forever if water seeps in at the rate of 10 cm / year and is removed at the rate of 10 cm / year because the same amount of water enters the underground which can be pumped from the soil. If more water is extracted from the soil as compared to it seeps, so with the passage of time water concentration in the soil decreases and in the last it disappeared.

answer; 60-100; beats per minute