You spend 1/2 of your allowance on Monday. On Tuesday, you spend 1/2 of the amount you have left. On Wednesday, you spend half of what remains. What fraction of your allowance do you have left?

1/2 + (1/2 * 1/2) + (1/2 * 1/2 * 1/2)

1/2 + 1/4 + 1/8

4/8 + 2/8 + 1/8 = ? you've spent.

Subtract that from 8/8

1 1/2 is the answer

To find out what fraction of your allowance you have left after spending on Monday, Tuesday, and Wednesday, you can follow these steps:

1. Start with your total allowance, which we'll call x.
2. On Monday, you spend 1/2 of your allowance, so you have x - 1/2x = 1/2x left.
3. On Tuesday, you spend 1/2 of what's remaining, which is 1/2x. Therefore, you have (1/2x) - 1/2(1/2x) = 1/2x - 1/4x = 1/4x left.
4. On Wednesday, you spend 1/2 of what's remaining, which is 1/4x. Thus, you have (1/4x) - 1/2(1/4x) = 1/4x - 1/8x = 1/8x left.

Therefore, the fraction of your allowance left after spending on Monday, Tuesday, and Wednesday is 1/8x.