Add 2/5 + 2/3, but first change the fractions so that they have an equal denominator. Since 3 and 5 (the denominators) both have 15 in common lets multiply 2/5 by 3/3 which gets you 6/15. 2/3 x 5/5 equals 10/15. 6/15 + 10/15= 16/15. Don't change 16/15 into a mixed number yet we still have to subtract 1/4 cup of liquid (after it's boiled) from the total amount of liquid (before it's boiled): 16/15. 16/15 and 1/4 don't have the same denominator, we're going to have to change that. 15 and 4 both have 60 in common. So now let's multiply 1/4 by 15/15 which equals 15/60. Now we're going to change 16/15 by multiplying it by 4/4 which equals 64/60. Finally, we're going to subtract 64/60 - 15/60=49/60.49/60 cups of broth is left after its boiled.