Salt Water

A tank has pure water flowing into it at 10 l/min. The contents of the tank are kept thoroughly mixed, and the contents flow out at 10 l/min. Salt is added to the tank at a rate of 0.1 kg/min. Initially, the tank contains 10 kg of salt in 100 l of water.

Devise a function whose argument is time t. The function returns the amount of salt (kg) left in the tank after t minutes rounded to 3 decimal places.

Examples

salt(0) ➞ 10.0

salt(5) ➞ 6.459

salt(10) ➞ 4.311

salt(120) ➞ 1.0

Notes

• Assume the added salt has a negligible effect on the volume of the liquid in the tank.
• Keep in mind the amount of salt in the tank is changing continuously.