GMAT Prep Question

[raviram1980]

Hi

Could some explain this question

If M>0 and N>0, is M+X/N+X > M/N ?

1) M<N
2) X>0

We cannot cross multiply without changing the sign of the inequality unless we know the sign of the variable? Based on this could we simplify the given expression?

Thanks

[raviram1980]

Could someone please reply here?

Thanks

[omkar.nadgauda]

I will try my best.

The problem is actually testing the proper/improper fraction concept. Inequality is just to confuse people.

I will go with C.

My reasoning : if M<N then it is a proper fraction and when you add a positive constant to both numerator and denominator of proper fraction, its value increases. So the first one states that its a proper fraction while the second one suggest it is an addition (+ve constant).

[raviram1980]

Thanks I understand your explanation.

But still I have this question

We cannot cross multiply without changing the sign of the inequality unless we know the sign of the variable?

And if there was another question involving inequality and variable is this something to keep in mind.

Thanks

[omkar.nadgauda]

Thanks I understand your explanation.

But still I have this question

We cannot cross multiply without changing the sign of the inequality unless we know the sign of the variable?

And if there was another question involving inequality and variable is this something to keep in mind.

Thanks

Yes, definately. We do not know the sign of variable. So we need to be careful. Similar caution needs to be taken during absolute values and during even powers.

[StaceyKoprince]

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