In order to calculate the rate of cups of flour to stick of butter, just calculate the following quotient:
(1 1/4)/(7/8) = (5/4)/(7/8) = 5·8/7·4 = 40/28 = 20/14 = 10/7
Hence, the required rate is 10/7 or 10:7
that is, 10 cups of flour for 7 sticks of buttter
