Query about Question 2 from "PrepSwift: Brute Force" [912]

GRE GRE Quant Problem Solving
1

https://prepswift.gregmat.com/quizzes/quiz/prepswift-brute-force (Question 2)

How does S[n/2] mean that we can do s3 and s4 to equal 7. Don’t understand at all

2

First, evaluate the subscript, [n/2] alone to get 3, and then substitute it back as a subscript.

Refer to below image

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