Question

A tree measures 40 1/2 feet tall it grew 57 feet over the next 7 1/2 years. During 7 1/2 years what was the average yearly growth rate.

Answer 1

2 1/5 per year

Explanation:

First subtract how tall it was 7 1/2 years ago from how tall it is now.

57 - 40 1/2 =

57 - 40.5 = 16.5 or 16 1/2

So in the 7 1/2 years the tree grew 16 .5 or 16 1/2 feet. To get the average yearly growth for the 7 1/2 year period you have to divide the 16 1/2 feet by 7 1/2 years.

It makes it much easier if you change the fractions to decimals.

16 1/2 = 16.5

7 1/2 = 7.5

16.5 ÷ 7.5 = 2.2 or 2 1/5 feet per year