The total amount of money from washing cars is 3 * $10 = $30. The total amount of money from mowing lawns 2 * $13 = $26. The total amount of money Stormi makes is $30 + $26 = $56. Stormi still needs to make $80 - $56 = $24.
The answer: 24
Reverse engineering the question: Stormi is saving up to buy a bicycle. She washes 3 cars for $10 each. She mows 2 lawns for $13 each. If the bicycle she wants costs $80, how much more money does Stormi need to make to afford the bicycle?

Winwin paid $50 x 20 / 100 = $10 for the tax. So, she has $50 - $10 = 40 after paying the tax. Therefore, Winwin was able to take home $40 - $5 = $35 after she paid for the processing fee.
The answer: 35
Reverse engineering the question: Winwin won $50 in a lottery. She paid 20% for the tax and she paid $5 for the processing fee. How much was she able to take home?

Ray gave 25 * 2 = 50 cents to Randi. Ray has 95 - 25 - 50 = 20 cents in nickels left. Ray has 20 / 5 = 4 nickels.
The answer: 4
Reverse engineering the question: Ray has 95 cents in nickels. If Ray gives 25 cents to Peter, and twice as many cents to Randi as he gave to Peter, how many nickels does Ray have left?

He sold 2 * 25 = 50 amulets. So he made 40 * 50 = $2000. The faire took 2000 * .1 = $200. So he kept 2000 - 200 = $1800. The amulets cost 50 * 30 = $1500 to make. So he had a profit of 1800 - 1500 = $300.
The answer: 300
Reverse engineering the question:
Dirk sells amulets at a Ren Faire. He sells for 2 days and each day he sells 25 amulets. Each amulet sells for 40 dollars and they cost him 30 dollars to make. If he has to give 10% of his revenue to the faire, how much profit did he make?