Before you start to calculate 40 Cups, you should know the conversion rate between Cups and Ounce.
The rate is 9.6125E-15 and the math equation is 40 X 9.6125E-15 = 3.845E-13 .
Quick conversion chart of Cups to Ounces
1 Cup to Ounce = 9.6125E-15 Ounce5 Cup to Ounce = 4.80625E-14 Ounce10 Cup to Ounce = 9.6125E-14 Ounce20 Cup to Ounce = 1.9225E-13 Ounce30 Cup to Ounce = 2.88375E-13 Ounce40 Cup to Ounce = 3.845E-13 Ounce50 Cup to Ounce = 4.80625E-13 Ounce75 Cup to Ounce = 7.209375E-13 Ounce100 Cup to Ounce = 9.6125E-13 Ounce