Two numbers add up to 72. One number is twice the other. Find the numbers.

Let me see...

Let x = one number

Let 2x = the other number

x + 2x = 72

3x = 72

x = 72/3

x = 24

Of course, 2x becomes 2(24) or 48.

The numbers are 24 and 48.

Check:

Let x = 24

x + 2x = 72

24 + 2(24) = 72

24 + 48 = 72

72 = 72

Looks ok to me. What do you say?