Question

Amanda exercised for 10 minutes every day in the first week, 20 minutes in the second week, 30 minutes in the third week, and 40 minutes in the fourth week.

Billy exercised for 5 minutes every day in the first week, 10 minutes in the second week, 20 minutes in the third week, and 40 minutes in the fourth week.

Which statement best describes the methods used by Amanda and Billy to increase the time they spent exercising?


A) Amanda's method is linear because the number of minutes increased by an equal number every week.
B) Billy's method is linear because the number of minutes increased by an equal factor every week.
C) Both Billy's and Amanda's methods are exponential because the number of minutes increased by an equal factor every week.
D) Both Billy's and Amanda's methods are exponential because the number of minutes increased by an equal number every week.

Answer 1

Amanda linear, Billy exponential
ans: A

Answer 2

A) Amanda's method is linear because the number of minutes increased by an equal number every week.

Explanation:

Amanda's method is linear because the number of minutes increases by an equal number of minutes every week, that is 10 minutes.

1st week 0 + 10 = 10

2nd week 10 + 10 = 20

3rd week 20 + 10 = 30

4th week 30 + 10 = 40

Whereas Billy's equation forms like
`5(2)^x` where x is weeks.

Each week Billy is increasing his time two times or double.

So, Amanda's method is linear and Billy's method is exponential.

Option A is correct.