Question

After one customer buys 4 new tires, a garage recycling bin has 20 tires in it. After another customer buys 4 tires, the bin has 24 tires in it.

What is the explicit formula to represent the # of tires in the bin as an arithmetic sequence? And how many tires are in the bin after 9 customers buy all new tires?

Answer 1

its (24) 4×9=36. so (36 +24 =60) so there is 60 tires in the bin

Answer 2

Arithmetic sequence formula is:
`a_n = 20 + (n - 1) * 4`

After 9 customers there are 52 tires in the bin

Explanation:

The general arithmetic sequence formula is:

`a_n = a_1 + (n - 1) * d`

where
`a_1` is the first term,
`a_n` is the nth term, n is the term position and d is the common difference.

Assuming
`a_1` = 20

The second term is 24, then:

`24 = 20 + (2 - 1) * d`

d = 24 - 20 = 4

So, for this case, the arithmetic sequence formula is:

`a_n = 20 + (n - 1) * 4`

With n = 9:

`a_9 = 20 + (9 - 1) * 4`

`a_9 = 52`