Question

Tim planted a tree that was 36 in tall. The tree grew 3/4 in per year. That tree is now 43 1/2 in tall.how many years ago did tim plant the tree

Answer 1

43.5-(3/4)*x=36
x=(4/3)*(43.5-36)

Answer 2

The tree was planted 11 years ago.

Explanation:

This is an example of arithmetic progression.

First term, a = 36 inch.

Common difference, d = 3/4 = 0.75 inches.

We have equation for n th term = a + (n-1)d

That tree is now 43 1/2 in tall

That is

43.5 = a + (n-1)d = 36 + (n-1) x 0.75

(n-1) x 0.75 = 7.5

n - 1 = 10

n = 11

The tree was planted 11 years ago.