Lenny is making his own laundry soap. The recipe calls for 2 part 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? (1 point)
A. 7 cups
B. 21 cups
C. 28 cups
D. 14 cups
The ratio of soap flakes to borax and washing soda combined is 1:2. This means that for every 1 cup of soap flakes, Lenny needs to use 2 cups of borax and washing soda combined. Since Lenny is using 7 cups of soap flakes, he will need 2 * 7 = <<7*2=14>>14 cups of borax and washing soda combined.
Therefore, the correct answer is D. 14 cups.
To find out how many cups of borax and washing soda Lenny needs, we first need to determine the ratios of borax, washing soda, and soap flakes in the recipe.
The recipe calls for 2 parts borax, 2 parts washing soda, and 1 part soap flakes. Since Lenny is using 7 cups of soap flakes, we can set up the following equation to calculate the quantity of borax and washing soda needed:
2x + 2x + x = 7
Adding the terms on the left side of the equation, we get:
5x = 7
To isolate x, we divide both sides of the equation by 5:
x = 7/5
So, each part of the recipe is equal to 7/5 cups.
Now, to find the combined quantity of borax and washing soda, we add the quantities for each ingredient:
2(7/5) + 2(7/5) = 14/5 + 14/5 = 28/5 = 5.6 cups
Therefore, Lenny needs 5.6 cups of borax and washing soda combined.
The answer is not listed in cups, so the closest option is:
C. 28 cups
According to the recipe, Lenny needs 2 parts of borax and 2 parts of washing soda for every 1 part of soap flakes.
Since he is using 7 cups of soap flakes, he will need:
- 2 parts of borax = 2 * 7 cups = 14 cups of borax
- 2 parts of washing soda = 2 * 7 cups = 14 cups of washing soda
Therefore, the combined amount of borax and washing soda that Lenny needs is 14 cups + 14 cups = 28 cups.
The correct answer is: C. 28 cups.