Question

Jed is baking shortbread for a bake sale. The recipe calls for 1 1 4cups of flour and 1 2stick of butter. How many cups of flour will Jed need if he uses 3 sticks of butter?

Answer 1

15/2 cups of flour!

Answer 2

Answer:
`7\frac12` cups of flour is required for 3 sticks of butter.

Explanation:

We assume that quantity of flour is proportional to butter.

Given : The recipe calls of
`1\frac14` cups of flour and
`\frac12` stick of butter.

Let
`x_1=1\frac14=(5)/(4)`
`y_1=(1)/(2)`

For
`y_2=3` , we will find
`x_2` by using formula of direct proportion:
`(x_1)/(y_1)=(x_2)/(y_2)`

`((5)/(4))/(\frac12)=(x_3)/(3)\\\\\Rightarrow\ (5)/(2)=(x_3)/(3)\\\\\Rightarrow\ x_3=(5)/(2)*3= \frac{15}2=7\frac12`

Hence,
`7\frac12` cups of flour is required for 3 sticks of butter.