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# If x and y are both odd prime numbers and x < y, how many distinct

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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
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2xy can be divide by 1, 2, x, y, 2xy, 2x, 2y, and xy which are 8 in number.
answer D
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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
N = a^p * b^q * c^r

a,b,c are primes

Number of factors = (p+1)(q+1)(r+1)
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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
Lets say x = 5 , y = 7 Thus 2xy = 70 = 2^1 X 5^1 X 7^1

Number of factors = (1+1)*(1+1)*(1+1) = 8

THus correct answer should be D
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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
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Bunuel wrote:
If x and y are both odd prime numbers and x < y, how many distinct positive integer factors does 2xy have?

A) 3
B) 4
C) 6
D) 8
E) 12

Solution:

We can let x = 3 and y = 5 Thus:

2 * 3 * 5 = 30

The factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. We see that 30 has 8 factors.

Alternate Solution:

Since 2xy = 2^1 * x^1 * y^1 and 2, x and y are all distinct prime numbers, the number of factors 2xy has is (1 + 1)(1 + 1)(1 + 1) = (2)(2)(2) = 8.

Answer: D
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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
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Re: If x and y are both odd prime numbers and x < y, how many distinct [#permalink]
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