https://prepswift.gregmat.com/quizzes/quiz/prepswift-greatest-common-factor-gcf (Question 2)
write your question here
For the below, why not 143, 147, and 154
\operatorname{gcd} (147, 154) \neq 1
I am wondering the same thing^. Why is 143,147, and 154 incorrect?
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.