Hello there! A. 3.75 hours is your answer.
Okay, so lets start by finding the unit rate. To find the unit rate, we can use this formula: total ÷ time = unit rate.
total (72 cookies) ÷ time (2.5 hours) = unit rate. (how many cookies she can decorate and bake in an hour)
72 ÷ 2.5 = 28.8 cookies an hour
Now that we have this information, replace the 180 cookies in for the total number and use algebra to solve.
180 cookies ÷ x time = 28.8
Since 180 is a little more than 2 times 72, A would best fit since 3.75 is much closer to 2.5 than the other options. To check this, we can place 3.75 in for x in 180 ÷ x = 28.8.
180 ÷ 3.75 = 28.8.
So, this is your correct answer.