Question

Every Saturday, Justin gets an allowance of $10 from his parents. During every week since Justin began getting an allowance, he spends $8 and saves the remaining $2 of his allowance before he receives his next allowance. The sequence shown represents the amount of money Justin has right before and right after he gets his allowance for six consecutive weeks, starting with $0.

0, 10, 2, 12, 4, 14, 6, 16, 8, 18, 10, 20
Explain why this sequence is or is not a function?

A.
This sequence is not a function because the amount $10 appears in the sequence more than once.

B.
This sequence is not a function because the sequence does not form a line.

C.
This sequence is a function because each input (odd terms in sequence) maps to one output (even terms in sequence).

D.
This sequence is a function because each output (even terms in sequence) maps to one input (odd terms in sequence).

Answer 1

The sequence is a function since,

1. It maps to a number from each of the numbers or points in it's domain set which is the set of positive integers
2. It maps to only one point from each point in it's domain set.

Explanation:

This sequence is a function whose domain is the set of positive integers.

The function is given by,

f(x) = 10 + (x -2) when x is even

= (x- 1) when x is odd

The sequence is a function since,

1. It maps to a number from each of the numbers or points in it's domain set which is the set of positive integers
2. It maps to only one point from each point in it's domain set.