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3 votes
Which pair of numbers is relatively prime

A. 57 and 96
B. 68 and 118
C. 70 and 195
D. 143 and 323

User Welch
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2 Answers

4 votes

Answer:

D is correct.

Explanation:

I just finished taking the quiz.

User Erikric
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4 votes
Without any calculations it's evident it can't be neither B (both numbers are even, so they're divisible by 2) nor C (the numbers end in 0 and 5, so they're divisible by 5).

A.

57=3\cdot19\\ 96=2^5\cdot3
Both numbers have a factor of 3, so they're not relatively prime.
That means it must be D. But, let's check it.


143=11\cdot13\\ 323=17\cdot19

Indeed, those two numbers are relatively prime.

User Nex Mishra
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8.2k points