(Mixture problem.) A tank contains 1000 L of water in which initially 100 g of salt is dissolved. Brine runs in at a rate of 10 L/min, and each liter (L) contains 5 g of dissolved salt. The mixture in the tank is kept uniform by stirring. Brine runs out at 10 L/min. Find the amount of salt in the tank at any time t.

Solve using differential equations