Question

Lee has 3 dog walking customers. Each month he gains another customer. Which arithmetic sequence represents the number of customers he has?

Group of answer choices

a1 = 3; an = an-1 + 1

a1 = 1; an = an-1 + 3

a1 = 1; an = an+1 + 3

a1 = 3; an = an+1 + 1

Answer 1

Given:

Lee has 3 dog walking customers.

Each month he gains another customer.

To find:

The arithmetic sequence that represents the number of customers he has.

Solution:

Initial number of customers = 3

First term :
`a_1=3`

Each month he gains another customer.

Common difference :
`d=1`

Recursive formula of an AP is

`a_n=a_(n-1)+d`

where, d is common difference.

Substituting d=1, we get

`a_n=a_(n-1)+1`

So, the required arithmetic sequence is
`a_n=a_(n-1)+1`, where
`a_1=3`.

Therefore, the correct option is A.