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.