Lesson: Operations with Fractions

Rate this video: 

Comment on Operations with Fractions

To solve this problem:

Let p = the product of all the odd integers between 500 and 598, and let q = the product of all the odd integers between 500 and 602. In terms of q, what is the value of 1/p + 1/q?

Are we to memorize the prime numbers between 500 and 1000? If yes then what are the set of numbers for which we should memorize the prime numbers for?
gmat-admin's picture

I think you might be mixing up ODD numbers with PRIME numbers.

Here's my full solution to your question: https://gmatclub.com/forum/let-p-the-product-of-all-the-odd-integers-bet...

ASIDE: As far as memorizing prime numbers goes, I think it's fine to remember the primes from 2 to 97

Sorry to mention this, but there is a typo in your answer to this question:
in this statement:
So, we know that x must be greater than 1/3 AND less than 1/3
I am certain you meant it to be:
So, we know that x must be greater than 1/3 AND less than 1/2
gmat-admin's picture

Good catch!! Thanks Aladdin!
I have edited my response.


Can you please explain the concept of the smallest number that denominator divides into? How to find that?
gmat-admin's picture

The technique for finding the Lowest Common Denominator is the same as finding the Least Common Multiple (LCM).

So, for example, when adding 1/12 and 7/15, we must first find the LCM of 12 and 15.

Here's a video on finding the LCM: https://www.gmatprepnow.com/module/gmat-integer-properties/video/835


Add a comment

Ask on Beat The GMAT

If you have any questions, ask them on the Beat The GMAT discussion forums. The average response time is typically less than 30 minutes.

Change Playback Speed

You have the option of watching our videos at various speeds (25% faster, 50% faster, etc). To change the playback speed, click the settings icon on the right side of the video status bar.

Have a question about this video?

Post your question in the Comment section below, and we’ll answer it as fast as humanly possible.

Free “Question of the Day” emails!