Question based on Primebox method--Ron Purewal Video.

[dddanny2006]

Hey Ron

I really enjoy your videos on Vimeo.Here's a question that I did not understand.

Original question-- Source:Ron's video on Vimeo

Is mn divisible by 40? ----------------Do we have 2x2x2x5
(1)m is divisible by 10
(2)n is divisible by 4

In the video we directly overrule St1 and St2 individually.Im confused as a result.Here's my method to it.Please correct me if Im wrong.

Statement 1 --Primebox for m includes 2,5.....?????
We need two more 2's and a 5.If at all they do come,from where will they come?Will they come from the "2,5,......?"the dots that Ive bolded?Or will they come from n.St1 mentions nothing about n.

Since we may or may not get a 2x2x2x5 Statement 1 is insufficient.

Similar is the case for statement 2 as well, here we have 2,2.....??? .We need one more 2 and a 5.We are not sure whether we'll have them or not.Again the same question,if we have them where will they come from?Will they again emerge from those dots"....???" that Ive bolded,or from m in this case? Or can they be a combination from both m as well as the dots..This too is insufficient.

C is the answer.


Thanks Ron

[RonPurewal]

Hi,
This folder is for problems from the MGMAT CAT exams only. Please re-post the problem in the General Math folder.

Thanks.