Q:

Chanda can bake and decorate 72 cookies in 2.5 hours. At this rate,how long will it take her to bake and decorate 108 cookies?A. 3.75 hoursB. 43.2 hoursC. 36 hoursD.14.4 hoursplease help if you can,and thank you very much if you do!​

Accepted Solution

A:
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 hourNow that we have this information, replace the 180 cookies in for the total number and use algebra to solve.180 cookies ÷ x time = 28.8Since 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.