1 quart = 4 cups. In order to solve your problem, you can cross multiply:
1/4 = x/40 multiply 1 and 40, and then multiply "x" and 4:
40 = 4x now, you must isolate the "x." To do so, use the opposite operation in which the "x" is involved in. Here we have 4x (the x is multiplied to the 4) so we must divide 4 from 4x. This cancels the 4 and leaves us with just "x".
What you do to one side, you must do to the other. So you also divide 40 by 4, which is 10.
Answer: 10 = x, therefore, there are 10 quarts in 40 cups.
