perplexus.info :: Just Math : LCM by pairs

LCM by pairs (Posted on 2013-10-14)

Determine the total number of pairs (x, y) of positive integers such that the least common multiple (LCM) of x and y is 2³*5⁷*11¹³.

No Solution Yet Submitted by K Sengupta

No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)

answer - spoiler

| Comment 1 of 4

The number of un-ordered pairs is .5*(3+1)*(7+1)*(13+1)=224

The number of ordered pairs is (3+1)*(7+1)*(13+1)=448

Posted by Ady TZIDON on 2013-10-14 10:27:53

Please log in:

Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (0)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info