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by liferocks » Tue Jun 08, 2010 9:55 pm
IMO ans is option C
35x and 20y has 5 in them so depending on values of x and y all the options can be HCF but 35x will never be divisible by 20x.Hence the ans
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by Patrick_GMATFix » Tue Jun 08, 2010 10:14 pm
When a number is divided by its factor, the result is always an integer. For example 12/3 or 12/6 are integers because 3 and 6 are factors of 12.

35x/20x is not an integer, so 20x cannot be a factor of 35x. As a result, 20x cannot be the greatest common factor of 35x and anything else (since it's not even a factor of 35x alone).

The answer is C

You can practice similar questions from the drill engine by setting topic='number properties' and difficulty='600-700'


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