Question

Mr. Arellano decided to make cookies for 7th grade students. He was supposed to mix 4 cups of flour, 1.2 cups of sugar, and 2.5 cups of chocolate chips to make 200 cookies, Mr. Arellano discovered the bag of flour he bought only has 2 cups of flour. How many cups of sugar and chocolate chips should Mr. Arellano use to keep the recipe proportional?

Answer 1

Answer:

0.6 cups of sugar and 1.25 cups of chocolate chips

Step-by-step explanation:

We can begin to solve this problem with a simple proportion:

$\frac{4}{2}$ = $\frac{1.2}{x}$ = $\frac{2.5}{y}$

(x = the new # of sugar    y = new # of chocolate chips)

In order to keep everything proportional, we must abide by the scale factor shown with the the flour.

Basically, if we're going to use three times the amount of flour we actually need, then we need to triple all our other ingredients.

We can see that the scale factor is one half, so

x = 1.2 * 0.5

and

y = 2.5 * 0.5

This means that:

x = 0.6

y = 1.25

This means that he has to use 0.6 (or 3/5) cups of sugar and 1.25 (or 9/8) cups of chocolate chips.