Divisibility

[hannahyounis]

Hello,

I would appreciate some help with this question from the flashcards

1) Number Properties/ Divisibility Question 28

x is divisible by 144. If ∛x is an integer, then which of the following is ∛x definitely divisible by?

A) 4 B) 8 C) 9 D) 12


I understand the factorization of 144 [ 2,2,2,2,3,3] and the fact that ∛x will have at least 3 of everything in the above factorization. Therefore, we will add 2 twos and another 3 to have [2,2,2,2,2,2,3,3,3]

The answer states the following in the end " From this information we can definitely conclude that ∛x must have 2 twos and one 3 as a factor. 4 and 12 are the only numbers in the list we can guarantee factors of ∛x." !!!!!!

so 8 has 3 twos?!! 9 has two 3s?!! Why not them?

Sorry it might be totally obvious, but it's not registering right now.

Thank you

Hannah

[StaceyKoprince]

Please read (and follow!) forum guidelines when posting. This folder is for general strategy questions - how to study, etc.

Please post your question in the appropriate folder; the MGMAT flashcards supplement the MGMAT Strategy Guides and can be posted in those folders.

[hannahyounis]

My apologies Stacey. I will post this in the General Math forum. Thanks for the heads up.

Hannah

[StaceyKoprince]

No worries - but do read my post above more carefully! Because the flash cards are an MGMAT product, you should post in the MGMAT Strategy Guides folder.

The General Math folder is no longer active!