Question

4) To cook 10 cups of rice, Martha used 18 cups of water. If Martha cooks 12 cups of rice, how much water does she need?​

Answer 1

To cook 10 cups of rice, Martha used 18 cups of water. We know that this is a proportion of the amount of water needed to the amount of rice cooked:

10 cups of rice : 18 cups of water = x : y

We also know that x is the amount of water needed to cook 12 cups of rice.

To find out how much water Martha needs, we can keep the proportion and substitute the known value of x.

10 cups of rice : 18 cups of water = 12 cups of rice : y

We can cross multiply to get:

10 * y = 18 * 12

y = 18 * 12 / 10

y = 21.6 cups

Therefore, Martha needs 21.6 cups of water to cook 12 cups of rice.