Is X-Y divisible by 5?

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Re: Is X-Y divisible by 5?

by El Cucu » Fri Jul 03, 2009 11:17 am
doclkk wrote:Is X-Y divisible by 5?

1. X is divisible by 5
2. Y is divisible by 5

C Right?

Not [E]

GMAT Express on Iphone sucks =/
IMO should be C. If two numbers are divisible by 5, their sum or subtract is also divisible by 5. Any number divisible by 5 has the unit digit 5 or 0.
Cero is multiple of any number so if the result is cero, cero can also be divided by 5.

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by amitsahdev » Sat Jul 04, 2009 10:27 pm
Is X-Y divisible by 5?
1. X is divisible by 5
2. Y is divisible by 5

Answer should be C.
If an integer a is divisible by x and b is also divisible by x then (a+b) or (a-b) must be divisible by x. In this case x = 5. Thus, X-Y will be divisible by 5. Lets try this with a real example. Lets assume x=25 and y=125 then (25-125)=-100 which is divisible by 5. Again, if x+y--> 25+125=150 which is again perfectly divisible by 5.

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by madhur_ahuja » Sat Jul 04, 2009 11:11 pm
Agree with C