I spent 2/3 of my money at store A. I spent 1/3 of my money at store B. When I left store B I had $4. How much money did I have when I entered store A?

Answer 1

(2/3)(1/3)x = 4
2/9 x = 4
x = 18

check:
spent 12 at A leaving 6
spent 2 at B, leaving 4

Answer 2

Imagine that there are 3 parts of a number. Then, you mark down 2 of them. Now, you are left with 1 part. Since the question asks 1/3 of the remainder, you should separate the last part into 3 parts. After that, you take 1 part away. You are left with 2 small parts. The 2 small parts are $4 in total, with means 4 / 2 = 2. 2 * 3 = 6. 6 * 3 = 18

That's the answer!