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Co-primes are integers that have no factors in common other than 1.Alphonsaj wrote:In how many ways can 480 be expressed as a product of two positive integers that are relatively prime (co-prime) to each other?
A) 24
B) 12
C) 4
D) 8
E) 2
The prompt should make clear that xy and yx are to be considered the same product.
480 = (2�)(3)(5).
From the prime-factorization above, we can form the following factor pairs that have a product of 480 and are co-primes:
(1)(2�3*5)
(2�)(3*5)
(3)(2�5)
(5)(2�3).
Total ways = 4.
The correct answer is C.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
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