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PLEASE HELP RIGHT AWAY!!1

PLEASE HELP RIGHT AWAY!!1-example-1

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4 votes

Answer:

3,172

Explanation:

The "Money saved that week" is an arithmetic progression, where the next term is found by adding a constant value to the previous term. In this case, the variation is 2.

So that could be modeled with this equation:
a_(n) = a_(1) + (n-1)V

Where a1 is the first term of the series, in our case: 10, and the V is the variation each week, in our case: 2.

To be able to calculate the overall sum and answer the question, we first need to calculate the amount she will save on the last week (n=52).


a_(52) = 10 + (52-1) * 2 = 10 + 102 = 112

Now that we know she'll save $112 on the 52nd week, let's calculate the total, using this formula:


S_(n) = ((a_(1) + a_(n)) * n)/(2)

We know n (52), a1 (10) and an (112), so...


S_(52) = ((10 + 112) * 52)/(2) = (122 * 52)/(2) = 3,172

At the end of the year, she will have saved $3,172

User HarshMarshmallow
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