Query about Question 2 from "PrepSwift: Greatest Common Factor (GCF)" [4138] - alternate answers

[user9441]

https://www.gregmat.com/quizzes/quiz/prepswift-greatest-common-factor-gcf (Question 2)

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Why can’t the answer to this question also be 75, 143 and 154? Aren’t those numbers co-prime too?

[cylverixxx]

Query about Question 2 from "PrepSwift: Greatest Common Factor (GCF)" [4138]

I’ve answered it above, but if you need more elaboration: The question is asking you to pick 3 numbers that are pairwise coprime. In other words, for every pair of different integers you pick from your set of 3, their greatest common divisor must be 1 (each pair (a,b) must be coprime). If we look at your set \{143, 147, 154\}, the pair (147, 154) is clearly not coprime, so this set of 3 doesn’t work.

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