Percentage Question

Question

you are making cupcakes for bake sale. 24 are vanilla, 36 chocolate. you want chocolate cupcakes to make up 70 percent of total number of cupcakes. Write and solve proportion to find number of chocolate cupcakes that need to be added. 

 

pls explain/ show work 

Answer 1

C = total number of cupcakes

 

.70C = number of chocolate cupcakes

.70C - 36 = number of additional chocolate cupcakes needed.

 

Since you already have 24 vanilla cupcakes, this can represent 30% of the total

So another way to express the total is C = 24/.3 = 80

 

80 - 24 - 36 = number of additional chocolate cupcakes needed

20 additional chocolate cupcakes are needed.