Question

If the length of a sea turtle is

directly proportional to its age,
and a 2-year old sea turtle is 3
inches long, how many feet long
is a 80-year old sea turtle?

Answer 1

10 feet

Explanation:

Let the length and the age of the sea turtle be L inches and A years old respectively.

Since its length is directly proportional to its age,

L= kA, where k is an unknown constant.

Let's find the value of the constant k.

L= kA

When L= 3, A= 2,

3= k(2)

2k= 3

k= 3 ÷2

`k = (3)/(2)`

Substitute the value of k back into the equation:

`L = (3)/(2) A`

When A= 80,

`L = (3)/(2) (80)`

L= 120

Length of sea turtle

= 120 inches

= (120 ÷12) feet

= 10 feet