Question

Erian's extended family is staying at the lake house this weekend for a family reunion. She is in charge of making homemadepancakes for the entire group. The pancake mix requires 2 cups of flour for every 10 pancakes.[a] Write a ratio to show the relationship between the number of cups of flour and the number of pancakes made.[b] Determine the value of the ratio.c Use the value of the ratio to fill in the following two multiplicative comparison statements..The number of pancakes made is.times the amount of cups of flour needed.The amount of cups of flour needed isof the number of pancakes made.(d If Erian has to make 70 pancakes, how many cups of flour will she have to use?

Answer 1

(a) The ratio is:

`\frac{\text{ number of cups of flour}}{\text{ number of pancakes}}`

(b) This ratio is equal to:

`\begin{gathered} \frac{\text{ number of cups of flour}}{\text{ number of pancakes}}=(2)/(10) \\ S\text{implifying} \\ \frac{\text{ number of cups of flour}}{\text{ number of pancakes}}=(1)/(5) \end{gathered}`

(c) Isolating "number of cups of flour":

`\text{ number of cups of flour}=(1)/(5)\cdot\text{number of pancakes}`

Isolating "number of pancakes":

`5\cdot\text{ number of cups of flour}=\text{ number of pancakes}`

The number of pancakes made is 5 times the amount of cups of flour needed.

The amount of cups of flour needed is 1/5 of the number of pancakes made.

(d) Substituting with "number of pancakes" = 70, we get:

`\begin{gathered} \text{ number of cups of flour}=(1)/(5)\cdot\text{7}0 \\ \text{ number of cups of flour}=14 \end{gathered}`

She will have to use 14 cups of flour