Question

A tree grows 1.5 feet per year. The tree is now 6 feet tall. Which sets of steps show ways to determine how many years the tree will take to be 27 feet tall?

Select the TWO correct answers.

A. 1.5x+6=27
1.5x=21
x=14
The tree will take 14 years to be 27 feet tall.

B. 27-6=21
21÷1.5=14
The tree will take 14 years to be 27 feet tall.

C. 1.5(x+6)=27
x+6=18
x=12
The tree will take 12 years to be 27 feet tall.

D. 1.5x+6=27
x+6=18
x=12
The tree will take 12 years to be 27 feet tall.

E. 27÷1.5=18
18-6=12

Answer 1

The answers are A & B.

Answer 2

Explanation:

Answers are A and B.

Facts given are :

Current height = 6 ft

Growth per year = 1.5 ft

Final height = 27

Explanation for A:

Assume it takes 'x' number of years.

initial height + growth in 'x' years = Total height of the tree after 'x' years

6 + 1.5x = 27

1.5x = 27 -6 = 21

(1.5 can be written as 3/2) 3x/2 = 21

3x = 42

x = 14

hence, number of years = 14

Explanation for B:

After 'x' years,

Final height - initial height = Growth in 'x' years

27 - 6 = Growth in 'x' years

21=Growth in 'x' years = 1.5x

21= 3x/2

42=3x

14=x

hence, number of years = 14