Question

Alexandra uses 12 cups of water and 6 cups of dry rice to make 18 cups of cooked rice. Today, she wants to make 4 cups of cooked rice. Which proportion can Alexandra use to find r, the amount of dry rice to use to make 4 cups of cooked rice?

Answer 1

The proportion that Alexandra can use to find r is 9 cups of water and 4 cups of dry rice

If Alexandra uses 12 cups of water and 6 cups of dry rice to make 18 cups of cooked rice, this can be expressed as:

$\frac{12}{6} = 18cups$

To get the proportion "r" for the amount of dry rice to use to make 4 cups of cooked rice, we can write:

$r = 4 cups$

Divide both expressions:

$\dfrac{\frac{12}{6} }{\frac{a}{b} } =\frac{18}{4}\\\dfrac{12b}{6a}= \frac{18}{4}\\\dfrac{2b}{a} =\frac{18}{4}\\\frac{b}{a} =\frac{18}{8}\\\frac{b}{a} =\frac{9}{4} =r$

Hence the proportion that Alexandra can use to find r is 9 cups of water and 4 cups of dry rice

Learn more on proportions here: brainly.com/question/19994681