Question

A hot chocolate recipe calls for three teaspoons of cocoa for every cup of milk.

Answer 1

To make a hot chocolate recipe,

It requires

`1\text{ cup of milk to 3 teaspoons of cocoa}`

Ratio of cup of milk to teaspoons of cocoa is

`1\colon3`

Let k represent the number of cups of milk needed for 9 teaspoons of cocoa

To find k by crossmultiplying,

`\begin{gathered} \text{If 1 cup of milk is to 3 tsp of cocoa} \\ k\text{ cups of milk is to 9 tsp of cocoa} \\ \text{Crossmultiply} \\ k*3=1*9 \\ 3k=9 \\ \text{Divide both sides by 3} \\ (3k)/(3)=(9)/(3) \\ k=3 \end{gathered}`

9 teaspoons of cocoa will require 3 cups of milk

Hence, the answer is 3 cups of milk.

6 cups of milk will require

`=6*3=18\text{ tsp of cocoa}`

Hence, the answer is 18 teaspoons of cocoa.

7 cups of milk will require

`=7*3=21\text{ tsp of cocoa}`

Hence, the answer is 21 teaspoons of cocoa