Question

Joes bakery is making 168 cupcakes for a large catering order. Their recipe calls for 5 ounces of flour for 12 cupcakes. How much flour will they need for their catering order? Enter a whole number pounds (IB) and enter the ounces ( oz ) as a number between 0 and 15, using the fact that 1 IB = 16 oz.

Answer 1

We have to find the amount of flour needed.

The order is 168 cupcakes.

The proportion between cupcakes and flour is: 5 ounces of flour for 12 cupcakes.

Then, we can use the rule of three to find the total amount of flour needed:

$\begin{gathered} 12\text{ cupcakes}\longrightarrow5\text{ oz of flour} \\ 168\text{ cupcakes}\longrightarrow x=168\cdot\frac{5}{12}=70\text{ oz of flour} \end{gathered}$

We can now express it in pounds and ounces using the fact that 1 lb = 16 oz.

We start by calculating how many pounds is 70 oz and then complete the decimal part expressed in ounces:

$\begin{gathered} 70\text{ oz}\cdot\frac{1\text{ lb}}{16\text{ oz}}=4.375\text{ lb} \\ 0.375\text{ lb}\cdot\frac{16\text{ oz}}{1\text{ lb}}=6\text{ oz} \\ \Rightarrow70\text{ oz}=4\text{ lb }6\text{ oz} \end{gathered}$

Answer: The amount of flour needed is 4 lb and 6 oz.