Question

Nick opens a savings account with $50. Each week after, he deposits $15. In how many weeks will he have saved $500?

Answer 1

After `30` weeks he has `$500`

Explanation:

We are working with an arithmetic series, where each term representswthe total in the account after `15` is added each week.

The sequence is `" "50," "65," "80," "95 ....... 500`

We are looking for `(n-1)` weeks

After 1 week, we have the 2nd term,
After 2 weeks we have the 3rd term ....

We know that `T_n = $500," " a = 50," " d = 15`

`Tn = a +(n-1)d`

`50+(n-1)15 = 500`

`(n-1)15 = 500-50 =450`

`n-1 = 450/15 = 30`

Therefore after 30 weeks he has `$500`