Mary sells lemonade, and she donates 10 cents from every cup she sells to charity. The cups of lemonade sell for 45 cents. One day she made $17.10. How much money did she give to charity that day?
My answer would be $3.80 is what she gave to charity.
I first started with how many cups she sold. 38 times .45 = $17.10. She sold 38 cups. So now we find how much she donated to charity. 38 times .10 = $3.80.
