GMAT Prep PS 1

I can type the square sign, so consider * as replacement.

*m = 3m , if m is odd
*m = m/2 , if m is even

*9 = 3*9 (as 9 is odd) = 27
*6 = 6/2 (as 6 is even) = 3

=> *9 x *6 = 27 x 3 = 81

*27 = 3*27 (as 27 is odd) = 81 = *9 x * 6 , so this is our answer, D

For the rest of the options, the value is not equal to 81.
For example, the one you have selected i.e

*36 = 36/2 (as 36 is even) = 18.[/spoiler]

Last edited by anshumishra on Sat Jan 22, 2011 9:54 am, edited 1 time in total.

Thanks
Anshu

(Every mistake is a lesson learned )

Quote

adwaitkasbekar: Junior | Next Rank: 30 Posts; Posts: 16; Joined: Sun Nov 14, 2010 11:01 pm

by adwaitkasbekar » Sat Jan 22, 2011 9:43 am

hi Anshu

I am afraid the answer is not 81 but D 27.

Quote

anshumishra: Legendary Member; Posts: 543; Joined: Tue Jun 15, 2010 7:01 pm; Thanked: 147 times; Followed by:3 members

by anshumishra » Sat Jan 22, 2011 9:52 am

adwaitkasbekar wrote:hi Anshu

I am afraid the answer is not 81 but D 27.

Right, that is what we calculated.

Please note that : *9 x *3 = 81
and *27 = 81
The option *81 = 81 x 3 = 243 (is clearly wrong)

Hence, *9 x *3 = 81 = *27 (so, the answer is D -> *27 or 27 inside square bracket). Let me add the spoiler in my solution so you know that the answer we calculated was D only.

Thanks
Anshu

(Every mistake is a lesson learned )