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 should he use?
First, we need to determine how many cups of borax and washing soda Lenny should use in total. The recipe calls for 2 parts borax + 2 parts washing soda + 1 part soap flakes, which totals to 5 parts in total.
To find the number of cups of borax and washing soda combined, we divide the total cups of soap flakes by the total number of parts and multiply by the number of parts for borax and washing soda.
Cups of borax + washing soda = (7 cups soap flakes / 5 parts) * 4 parts = 28 cups / 5 = <<7=7>>7 cups.
Lenny should use 7 cups of borax and washing soda combined.