Lenny is making his own laundry soap. The recipe calls for 2 parts borax, 2 parts washing soda, and 1 part soap flakes. If Lenny uses 7 cups of soap flakes, how many cups of borax and washing soda combined does he need?

Options:
7 cups
21 cups
14 cups
28 cups

1 answer

Since the ratio of borax to washing soda is 2:2 (or 1:1), Lenny needs the same amount of both.

Since the recipe calls for 1 part soap flakes and Lenny is using 7 cups of soap flakes, he needs 7 cups of both borax and washing soda combined.

Therefore, the answer is 7 cups.