Question 1185225: Suppose that you plan on taking a summer job selling magazine subscriptions. The magazine company will pay you $1.25 for selling the first subscription. For each additional subscription​ sold, the magazine company will pay you 15 cents more than what was paid for the previous subscription. How much will you earn by selling 150 magazine​ subscriptions?
Answer by greenestamps(13203)   (Show Source):
You can put this solution on YOUR website!
The dollar amounts form an arithmetic sequence of 150 terms with first term 1.25 and common difference 0.15: 1.25, 1.40, 1.55, ...
The sum of the terms of an arithmetic sequence is
Sum = (number of terms) times (average of all the terms)
In an arithmetic sequence, because of the constant spacing between terms, the average of all the terms is the average of the first and last terms.
So to find the answer to the question, you can do the following:
(1) determine the 150th (last) term: first term plus 149 times the common difference;
(2) find the average of the first and last terms; and
(3) multiply that average by the number of terms, 150.
ANSWER: $1863.75
If all you want is the answer, there it is....
If you want to LEARN HOW to solve problems like this, perform the calculations I described and verify that you get the shown answer.
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