MGMAT: exponents

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 77
Joined: Sun Jun 21, 2009 10:25 am
Location: Germany
Thanked: 7 times

MGMAT: exponents

by Nermal » Sat Sep 12, 2009 1:43 am
If n is a non-negative integer such that 12^n is a divisor of 3,176,793, what is the value of n^12 - 12^n ?
A) - 11
B) - 1
C) 0
D) 1
E) 11
Last edited by Nermal on Sat Sep 12, 2009 6:55 am, edited 1 time in total.
Source: — Problem Solving |

Master | Next Rank: 500 Posts
Posts: 189
Joined: Thu Apr 03, 2008 2:03 pm
Location: USA
Thanked: 21 times

by rohan_vus » Sat Sep 12, 2009 4:27 am
IMO B .. Let me know if its correct ? I will give expln later

Senior | Next Rank: 100 Posts
Posts: 77
Joined: Sun Jun 21, 2009 10:25 am
Location: Germany
Thanked: 7 times

by Nermal » Sat Sep 12, 2009 6:57 am
rohan_vus wrote:IMO B .. Let me know if its correct ? I will give expln later
OA is B.
Good job, rohan_vus!

Senior | Next Rank: 100 Posts
Posts: 45
Joined: Wed Jun 11, 2008 4:25 pm
Thanked: 4 times
GMAT Score:730

by praky_rules » Sat Sep 12, 2009 9:22 am
12 is even. 12^n for all n > 1 has to be even. n is non negative. So n has to be zero.

n^12 - 12^n = 0-1=-1 B.

Master | Next Rank: 500 Posts
Posts: 399
Joined: Wed Apr 15, 2009 3:48 am
Location: india
Thanked: 39 times

by xcusemeplz2009 » Sat Sep 12, 2009 9:57 am
ans is -1
any number divisible by 12 has to be divisible by 2

since the given no. is odd , for it to be divisble by 12^n has to be divisble by 2^n and if n=0 then it is possible .

so 0^12-12^0=-1
It does not matter how many times you get knocked down , but how many times you get up