A tank initially contains 100 kg of salt dissolved in 1000 L of water. A solution with concentration 0.05 kg of salt per L of water begins entering the tank at the rate 6 L per hour. The solution is continually mixed (so that the concentration of salt is roughly uniform throughout the tank) and drains from the tank at the same rate that it enters. If y is the amount of salt (in kg) in the tank after t hours, a differential equation that models this situation is:

dydt=

and the initial condition for this differential equation is:

y(0)=