A certain boiler pipe will permit a flow of 35.5 liters/min. Buildup of scale inside the pipe eventually reduces its diameter to three-fourths of its previous value. Assuming that the flow rate is proportional to the cross-sectional area, find the new rate for the pipe.

Solution:

35.5/A = x/[(3/4)2 A]

x = 35.5*9/16 = 19.96875 liters/min