Question: Fractions in Ascending Order

Comment on Fractions in Ascending Order

how do we know that the middle number is the third number even thought the list have an odd number?
gmat-admin's picture

If five numbers are listed in ascending order, the 3rd number is the same as the middle number.

I think we can also use the denominator principle to rearrange and find out... greater denominator lower number...
gmat-admin's picture

We COULD do that, as long as the numerators are the same.
So, for example, to compare 5/8 and 10/18, we'd need to convert one of the fractions. We might rewrite 5/8 as 10/16, which means we are not comparing 10/16 and 10/18

Since 10/16 has the smaller denominator, we can conclude that 10/16 is the bigger fraction.

As you might imagine, this approach could be quite time consuming.

In the second approach how did u figure out 360 will divide all
gmat-admin's picture

36 is the biggest denominator, so the least common denominator will be a multiple of 36 (36, 72, 108, etc)

I also see that 5 is a denominator. So, the least common denominator will ALSO be a multiple of 5.

Since 36 is not divisible by 5, I multiplied 36 x 5 to get 180. So, the least common denominator must be a multiple of 180.

Then I checked to see whether 180 is a multiple of the other three denominators (8, 3, and 18).

180 IS a multiple of 3 and 18. BUT, 180 is NOT a multiple of 8.

So, I doubled 180 to get 360, which IS a multiple of 8

So, 360 is the least common multiple of 8, 3, 18, 5 and 36

Phew!!!!

Got it and thanks for fast answer and thanking you from my bottom of my heart to you for providing such kind of facility at our finger tips .

https://gmatclub.com/forum/if-r-and-s-are-two-positive-numbers-what-is-the-value-of-the-ratio-r-317669.html

Approach please sir

Scoring Algorithm

The GMAT scoring algorithm penalizes you much more for getting easy questions wrong than it rewards you for getting difficult questions right. So, it’s better to guess on hard questions so you’ll have enough time to answer easier questions.

Change Playback Speed

You have the option of watching the 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 a GMAT expert will answer it as fast as humanly possible.

Free “Question of the Day” emails!