For the sequence defined by C_n = (−1)^n*n +… | GMAT Sprint

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For the sequence defined by $C_{n} = (−1)^n*n + 5$ for all integers n ≥ 1, what is the 7th term of the sequence?

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-1

-2

Correct

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Explanation

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Official Explanation

Official

We have the sequence defined as C n =

(−1)^n × n + 5

for all integers n ≥ 1. To find C 7, we calculate: C 7 =…

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Comments

DanielMar 23, 2024

Thankss

AlessandroAug 14, 2024

Thank you very much!

FrancescoAug 23

thanks, this one was pretty straightforward once I remembered n starts at 1 not 0 lol

RishabhAug 29

same here, I almost plugged in 0 by habit 😅

AndrewAug 30

wait why is the term for n=7 not just plugging in? I got a positive number at first because I forgot the negative sign flips with odd powers

HungAug 31

yeah the (-1)^n part is the whole trick, odd n gives negative

ShreyaSep 4

ohhh that's what I missed, thanks!

What this question tests

What it tests

Your grasp of exponent rules — multiplying and dividing powers, power-of-a-power, and negative/zero exponents.

Common trap

Adding exponents when multiplying bases that have the same exponent, or confusing (x^a)^b with x^(a·b).

For the sequence defined by Cn=(−1)n∗n+5C_{n} = (−1)^n*n + 5Cn​=(−1)n∗n+5 for all integers n ≥ 1, what is the 7th term of the sequence?