50 !
the pump used to fill the water tank on a fire truck takes 40 minutes to fill the tank. if the pump sending water to the hose is on, it takes 60 minutes to fill the tank. if the pump filling the water tank is off, how long does the pump sending water to the hose take to empty the tank?
a)120 minutes
b)60 minutes
c)30 minutes
d)24 minutes

The manufacturer of a new product developed the following expression to predict the monthly profit, in thousands of dollars, from sales of the productwhen it is sold at a unit price of x dollars.-0.5x^2 + 22x - 224what is represented by the zero(s) of the expression? a.the profit when the unit price is equal to 0b.the unit price(s) when the profit is equal to 0c.the profit when the unit price is greatestd.the unit price(s) when profit is greatest