Calculus - Related Rate...?

#1 Water is poured into a rectangular box with a square base (4 cm x 4 cm x 12 cm) at a rate of 50 cm^3/min. What rate does the surface of the water rise?

V = h(l^2)

V = 12(l^2)

dV/dt = 24 = 24l(dh/dt)

50 = dV/dt = 24(4)(dh/dt)

50 = 96(dh/dt)

50/96 cm/min = dh/dt

#2 A cone is filled with water at a rate of 6m^3/min.

If the reservoir is 3 m deep, and has a 4 m radius at the top, what is the rate at which the surface level of the water is rising at the instant the depth of the water is 2 m?

**My answer:** dh/dt = 16/6pi.

Are these answers right?