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:

Thanks for challenging us. I am sure it is going to be [#permalink]
26 Jun 2004, 20:22

Thanks for challenging us. I am sure it is going to be useful to us .

Is 75/(Z+1) an integer?

1. Z is a multiple of 75.

2. 0 <= Z <=75.

Explanation to this question in the site is given below.

Explanation

Statement 1 states that Z is one of the following: -75, 0, 75, 150, etc
it is not sufficient since when Z is 0, the expression is an integer, in all other cases it is not. INSUFFICIENT.

Statement 2 gives a range of numbers where again, the expression may or may not be an integer (e.g. 4 and 5). INSUFFICIENT.

Combining both statements together, z can be 0 or 75 - sufficient.

Although, I did it wrong, I am not able to accept the answer C. The problem is if Z is 0, 75/(0+1) = 75. Integer; sufficient to say yes. However, if Z is 75, the answer is 75/(75+1) = 75/76 . Not an integer. However, here it is sufficient to say No. Therefore, for the answer has to be E. Can some one help me to understand whether I am wrong or the challenge question's explantaion is wrong?

Re: April-June GMAT Club Challenge Question 5 [#permalink]
26 Jun 2004, 23:51

dhandaydham wrote:

Thanks for challenging us. I am sure it is going to be useful to us .

Is 75/(Z+1) an integer?

1. Z is a multiple of 75.

2. 0 <= Z <=75.

Explanation to this question in the site is given below.

Explanation

Statement 1 states that Z is one of the following: -75, 0, 75, 150, etc it is not sufficient since when Z is 0, the expression is an integer, in all other cases it is not. INSUFFICIENT.

Statement 2 gives a range of numbers where again, the expression may or may not be an integer (e.g. 4 and 5). INSUFFICIENT.

Combining both statements together, z can be 0 or 75 - sufficient.

Although, I did it wrong, I am not able to accept the answer C. The problem is if Z is 0, 75/(0+1) = 75. Integer; sufficient to say yes. However, if Z is 75, the answer is 75/(75+1) = 75/76 . Not an integer. However, here it is sufficient to say No. Therefore, for the answer has to be E. Can some one help me to understand whether I am wrong or the challenge question's explantaion is wrong?

Thanks.

Yes, I answered E as well, you are right, dhandaydham. This happened to me too.

Re: April-June GMAT Club Challenge Question 5 [#permalink]
27 Jun 2004, 13:37

Expert's post

dhandaydham wrote:

Thanks for challenging us. I am sure it is going to be useful to us .

Is 75/(Z+1) an integer?

1. Z is a multiple of 75.

2. 0 <= Z <=75.

Explanation to this question in the site is given below.

Explanation

Statement 1 states that Z is one of the following: -75, 0, 75, 150, etc it is not sufficient since when Z is 0, the expression is an integer, in all other cases it is not. INSUFFICIENT.

Statement 2 gives a range of numbers where again, the expression may or may not be an integer (e.g. 4 and 5). INSUFFICIENT.

Combining both statements together, z can be 0 or 75 - sufficient.

Although, I did it wrong, I am not able to accept the answer C. The problem is if Z is 0, 75/(0+1) = 75. Integer; sufficient to say yes. However, if Z is 75, the answer is 75/(75+1) = 75/76 . Not an integer. However, here it is sufficient to say No. Therefore, for the answer has to be E. Can some one help me to understand whether I am wrong or the challenge question's explantaion is wrong?

Thanks.

Thank you for catching it.
My appologies, I failed to catch it when I was going through it.

Actually Kpadma was the first to catch it. The scores have been modified to reflect this change. We will start a discussion specifically for the challenge and will appreciate reports of any inconsistencies.

probably a stupid question, but how is 0 a multiple of 75.

Zero is an even integer and considered as a multiple of all the numbers. For example multiples of 5 means, 5, 10, 15, 20 so on. That is, 5 is multiplied by 1, 2, 3, 4, so on. In the same way, if you multiply 5 x 0 (the first integer) the value is zero. Remember this point. I was also perplexed first by this. However, I learned it slowly. Last some points for not knowing this in my diagnostic test. _________________

probably a stupid question, but how is 0 a multiple of 75.

Zero is an even integer and considered as a multiple of all the numbers. For example multiples of 5 means, 5, 10, 15, 20 so on. That is, 5 is multiplied by 1, 2, 3, 4, so on. In the same way, if you multiply 5 x 0 (the first integer) the value is zero. Remember this point. I was also perplexed first by this. However, I learned it slowly. Last some points for not knowing this in my diagnostic test.

No, zero is not a multiple of every non-zero integer, because 5 != 0*z, there is no z, such that: 5 = 0*z..!

Re: April-June GMAT Club Challenge Question 5 [#permalink]
28 Jun 2004, 19:18

bb wrote:

Thank you for catching it. My appologies, I failed to catch it when I was going through it.

Actually Kpadma was the first to catch it. The scores have been modified to reflect this change. We will start a discussion specifically for the challenge and will appreciate reports of any inconsistencies.

-Thank you.

Thanks for the forum and bringing in the challenge question section. I am a novice here. I hope to learn, and help others to learn while I learn. _________________

Emmanuel: then how can you say that from 1st statement the value of Z can be Zero.
As per (1) Z is a multiple of 75 and if Z=0 then is it feasible that still Z is a multiple of 75, bit confused here. I would have picked (A) as the answer.

No, zero is not a multiple of every non-zero integer, because 5 != 0*z, there is no z, such that: 5 = 0*z..!

I could not understand. Do you mind to explain it?

BY DEFINITION: a is divided by b if and only if there exists such k - integer, that a = k*b.

5 is divided by 0 if and only if there exists such k - integer, that 5 = 0*k = 0!!! => 5 is NOT divided by 0!

Well, if you divide 5 by zero the answer is infinite. Let me put the question in a different way. If zero is not considered as a multiple of every non-zero integer, for what non-zero integers you can consider zero is a multiple? In the explanation for the first statement they give zero is a multiple for 75. In other explanations too, I have seen zero is used as a multiple. Probably, you might be explaining some exceptions. Can you go a little bit down and explain things with some numbers so that we all can understand what you are saying? I hope I am not asking too much of your time. Thanks _________________