Question

Ernesto baked 3 cakes in 2 1/2 hours. Assume that the number of cakes baked varies directly with the number of hours. Write and solve a direct variation equation to find how many cakes can be baked in 7 1/2 hours.

Answer 1

We know that in 2 ½ hours (2.5 hours), we can create 3 cakes hence:

C = k t

where C is number of cakes, k is constant, and t is time

k = 3 cakes / (2.5 hours)

k = 1.2

C = 1.2 t

 

So for t = 7 ½ hours = 7.5 hours

C = 1.2 (7.5)

C = 9 cakes in 7 ½ hours