Question

Rhianna is baking a cake and some cookies for a party. She used 4 1/2 cups of flour for the cake. For each tray of cookies, she needs 2 1/2 cups of flour. She decides to use at least 15 cups of flour for the cake and the cookies.Assuming she can make fractional trays of cookies, how many trays, x, can she make?

Answer 1

The first step is to find how many cups of flour she has left to bake the cookies after baking the cake. To do it, substract the amount of flour she needs for the cake to the total amount of flour she decided to use.

`15-(4+(1)/(2))=15-4.5=10.5`

She has 10.5 cups of flour to bake the cookies. To find how many tray of cookies, solve the following equation for x:

`\begin{gathered} (2+(1)/(2))x=10.5 \\ (2.5)x=10.5 \\ x=(10.5)/(2.5) \\ x=(21)/(5) \end{gathered}`

She can make 21/5 trays of cookies. Written as a mixed number it is 4 1/5, it means she can make 4 1/5 or less trays of cookies.