Question

You have a 20-ounce bottle of juice. You pour out 1/4 of the bottle to share with a friend. If you pour out 3 ounces for yourself, what fraction of the 20 ounces will be left in the bottle?

Answer 1

Original capacity = 20 oz
1/4 of bottle = 20*(1/4) = 5 oz

Liquid left = 20-5-3=12 oz

Fraction left = 12/20 = 8/20 = 3/5

Another way using fractions:
3 oz out of 20 oz = 3/20
fraction left = 1 - 1/4 - 3/20 = (20-5-3)/20 = 12/20 = 3/5