Fatima wants to fill a circular wading pool.she does not have a hose, so she uses a rectangular pail that she fills from a tap. The inside diameter of the pool is 120 cm and it is 25 cm deep. The inside dimension of the pail are 30 cm x 22 cm x 24 cm deep. How many pails of does fatima have to carry to fill the pool to depth of 18 cm?