Ron's Study Hall dated June 10, 2010: Prime Boxes

[Nz]

Q. What is the least common multiple of x and 12?
1) The least common multiple of x and 9 is 45.
2) The lest common multiple of x and 4 is 20.

Ans: Stmt 1
This implies that x could be
3^0 times 5 = 5 or
3^1 times 5 = 15 or
3^2 times 5 = 45

Taking stmt 1) and the question prompt we get LCM of
5 and 12
15 and 12
45 and 12 respectively as
60, 60 and 180
We get different LCM's so Insufficient.

Stmt 2
Here, x could be:
5, 10, or 20
and LCM with 12 is the same for all the above values of x ie 60.
So Sufficient and Ans is (b)

Kindly let me know if my process for solving this is correct or not. Thanks!!

[tim]

Looks good to me!

[Nz]

Thanks Tim!
Hard to believe, I don't usually get them correct :)

[tim]

it should be encouraging to know that you're making improvement then; keep up the good work!