Question

A cookie recipe called for 3 ¼ cups of sugar for every 2 ⅓ cups of flour. If you made a batch of cookies using 4 cups of flour, how many cups of sugar would you need?

Answer 1

1) Gathering the data

3 ¼ cups of sugar------------------ 2 ⅓ cups of flour

x 4

2) Let's set a proportion, and then cross multiply those ratios but before that

let's convert those mixed numbers:

`\begin{gathered} 3(1)/(4)=(4*3+1)/(4)=(13)/(4) \\ 2(1)/(3)=(3*2+1)/(3)=(7)/(3) \end{gathered}`
`\begin{gathered} (13)/(4)-----(7)/(3) \\ x\text{ -------4} \\ (7)/(3)x=4*(13)/(4) \\ (7)/(3)x=13 \\ 7x=39 \\ x=(39)/(7) \end{gathered}`

So rewriting it above, we have. 39/7 as 39/7 is >1 then we can rewrite it into a Mixed Number:

3) Hence, I'll need 5 4/7 cups of sugar