A charity receives 405 dollars after a platform deducts a 10% fee from a donation. What was the donation before the fee? Enter the amount in dollars.
Correct answer
450
Explanation
After the fee, the charity receives 90% of the donation, so 405 / 0.90 = 450. Adding 10% of 405 gives 445.50 and fails because the fee was a percent of the original donation.