Thursday, September 16, 2010

If n is an integers, is n/15 an integer?

1) 3n/15 is an integer.

2)8n/15 is an integer







Rephrase the question: Does n's prime box have a '3 and a '5'.

1.) 3n/15 = n/5 Since this is an integer, we know that n is divisible by 5 . Therefore, n's prime box Includes a '5.' However, we do not know whether or not n is also divisible by 3, thus statement 1 is insufficient.

2.) 8n/15 = is also an integer, but if u look closely, you will see that 8 is not divisible by 15. Thus, for 8n/15 to be an integer, it must be that n is divisible by 15. Thus B is sufficient.

The answer is B.

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