A tank contains 4000 liters (L) of a solution consisting of 132 kg of salt dissolved in water. Pure water is pumped into the ta
nk at the rate of 12 L/s, and the mixturelong dashkept uniform by stirringlong dashis pumped out at the same rate. How long will it be until only 11 kg of salt remains in the tank?
we have that if in 4000 L/sol there is 132 kg salt and the pumping speed is 12L/s, we must find how much of salt is pumping per second and then find the amount of salt remaining
12L/s*132kg salt/4000L = 0.396 Kg salt/s, this means that 0.396 kg per second comes out
, It should be found that the amount of salt must be drained so that only 11 kg of salt remain
132kg salt - 11 kg salt = 121 kg salt, so
121Kg salt*s/0.396Kg salt ≅ 305.55 s ⇒ 305.55s*min/60s ≅ 5.09 min
