One serving is 3/4 cups of rice. To find out how many serving there are in 12 cups of rice, you divide 12 by 3/4. (When dividing fractions, don't ask why. Flip the second one over and multiply).
12/(3/4) = 12 *(4/3) = 48/3 = 16
There are 16 servings of rices in 12 cups.
