To solve this problem, you need to find the fraction of Katlyn's total allowance that she spent on food. First, let's find out how much money Katlyn had left after buying clothes. It says she had "of her allowance left." To find this amount, you would multiply her allowance by, since she had left. Next, you need to find out how much money she spent on food. It says she spent " of this money on food." To find this amount, you would multiply the amount she had left by, since that is the fraction she spent on food. To summarize, you would use the multiplication operation to solve this problem. First, multiply Katlyn's allowance by to find out how much money she had left after buying clothes.
Then, multiply that amount by to find out how much money she spent on food. So the correct answer is c. Multiplication.