Question

One cookie recipe calls for 2/3 cups of sugar another recipe calls for 1 1/4 cups of sugar. How many cups of sugar are needed in both recipes?

​

Answer 1

About 2 cups.

Explanation:

Use 3 and 4's LCM (Least Common Multiple).

3 and 4's LCM is 12.

Rewrite the fractions.

2/3 rewrites into 8/12.

1 1/4 rewrites into 1 3/12.

Add the fractions.

You should get 1 11/12.

Unfortunately there are no "cups" that go up to twelths. Here you will have to round.

1 11/12 is close to 2 cups.