Question

You have two recipes that together use a pound of butter. Once recipe takes 1/6 pounds more than the other one. How much butter in pounds does each recipe use?

Answer 1

7/12 lb and 5/12 lb

Explanation:

Since they add to 1 lb, and the difference in 1/6 lb, then one takes 1/12 lb more than 1/2 lb, and the other takes 1/12 lb less than 1/2 lb.

1/2 + 1/12 = 6/12 + 1/12 = 7/12

1/2 - 1/12 = 6/12 - 1/12 = 5/12

Answer: 7/12 lb and 5/12 lb

If you need to do it with an equation, then you can do it this way.

Let x = larger amount in one recipe. Let y = smaller amount in the other recipe.

The total is 1 lb, so

x + y = 1

The difference is 1/6 lb,

x - y = 1/6

Add the equations:

2x = 1 1/6

2x = 7/6

x = 7/12

x + y = 1

7/12 + y = 12/12

y = 5/12

Answer: 7/12 lb and 5/12 lb