Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

30sec
B it is
a/b*c/d = b/c*a/d
All we need to know is for a to be greater than d to create a larger product than b/c on the other side of the inequality. B gives that away
_________________

Whithout using any number, what you get from the stem is (a/b) (c/d)
in another way it is equal to a/d . c/b so greater than c/b if a/d > 1
That is exactly the purpose of second statement.

Thanks twixt. I still haven't got it. a/d has to greater than 1 provided b/c is not very small. Say if b/c is 0.001 and c/b is 1000, then does B alone anaswer the Q. so if a/d is 5 then, 5*0.001>1000 which is not true. If we reverse it, it becomes 5*1000>0.001. whic is true. So I am not sure if B alone can answer.
Plz bear with me as i am really not getting it.
S

Thanks twixt. I still haven't got it. a/d has to greater than 1 provided b/c is not very small. Say if b/c is 0.001 and c/b is 1000, then does B alone anaswer the Q. so if a/d is 5 then, 5*0.001>1000 which is not true. If we reverse it, it becomes 5*1000>0.001. whic is true. So I am not sure if B alone can answer. Plz bear with me as i am really not getting it. S

I am not sure what do you try to say here. The question does not ask you whether (a/b) x (c/d) > (b/c), unless you typed it wrong in the first place.

Re: If a, b, c, and d are positive integers, is (a/b) (c/d) > c/ [#permalink]
21 Mar 2013, 03:40

Expert's post

If a, b, c, and d are positive integers, is (a/b) (c/d) > c/b?

Is \frac{a}{b}*\frac{c}{d}>\frac{c}{b}? --> is \frac{c}{b}*\frac{a}{d}>\frac{c}{b}? --> since all variables are positive, then we can safely reduce by c/b: is \frac{a}{d}>1? --> cross-multiply: is a>d?