Max received an allowance of $20.she spent $12 and saved the rest. What percent of her allowance did she save?

100 * [(20 - 12) / 20] = ______%

40%

To find out what percent of Max's allowance she saved, you need to first calculate the amount of money she saved. In this case, she spent $12, so the amount she saved would be the difference between her allowance ($20) and the amount she spent ($12).

To calculate the amount saved:
Amount saved = Allowance - Amount spent = $20 - $12 = $8.

Now, to calculate the percentage, you will divide the amount saved by the total allowance and then multiply by 100.

Percentage saved = (Amount saved / Total allowance) * 100 = ($8 / $20) * 100 = 0.4 * 100 = 40.

So, Max saved 40% of her allowance.