She spent 25% and had $99 left.
$99 is 75% of the remaining money.
Divide to find the total remaining
99 / 0.75 = $132
Now she put 80% of her total earnings in the bank, this means the remaining amount is 20%.
Divide the remaining amount by 20%:
132 / 0.20 = $660
She earned $660 total.
