suppose we are given following problem.
A tank contains 50 gallons of a solution composed of 90% water and 10% alcohol. A second solution containing 50% water and 50% alcohol is added to the tank at the rate of 4 gallons per minute. As the second solution is being added, the tank is being drained at the rate of 5 gallons per minute. Assuming the solution in the tank is stirred constantly, how much alcohol is in the tank after 10 minutes? i guessed that it is related with differential equation,also i know that at time t=0,in tank there is 45 gallons water and 5 gallons alcohol,because per minute 4 gallons is added ,it means that 2 gallons water and 2 gallons alcohol is added so it one minute 7 gallons alcohol is in tank yes?and also because 5 gallons drained per minute ,we must substract 2.5 -2.5 each water and alcohol yes?please help me how to define how much alcohol will be in 10 minutes.