kevincan
In other words, how many distinct values can x/y have if x and y are both integers from 1 to 10?
(A) 63 (B) 65 (C) 67 (D) 69 (E) 71
My apologies for the error in the original!
This is really a gripping question!
We know that all pairs of (x,y) in which x and y have only 1 as their common factor form distinct values for x/y --> consider (x,y) in which x,y have common factor other than 1. They're:
(2,4) , (2,6) ,(2,8) , (2,10) , (3,6), (3,9), (4,6) , (4,8) , (4,10), (5,10) , (6,8) , (6,9), (6,10) , (8,10)
Each of these form 2 indistinct x/y --> 14*2= 28 indistinct x/y
2/2, 3/3, ......10/10 also form indistinct x/y --> 9 such x/y
---> the number of distinct x/y= 100 - 28- 9= 63
--== Message from the GMAT Club Team ==--
THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired. If you would like to discuss this question please re-post it in the respective forum. Thank you!
To review the GMAT Club's Forums Posting Guidelines, please follow these links:
Quantitative |
Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.