GMAT Forum

Combining exponents from GMAT PREP

Math problems from the *free* official practice tests and
problems from mba.com
Post a reply
nazimd73
Course Students
 
Posts: 2
Joined: Tue Sep 04, 2007 6:31 am
 

Combining exponents from GMAT PREP

by nazimd73 Wed Mar 18, 2009 9:57 pm

Hi,
Can someone help me solve this problem.

(5^21) x (4^11)= 2 x 10^n.


What is n
eileen1017
 
Posts: 11
Joined: Tue Jan 02, 2007 7:50 am
 

Re: Combining exponents from GMAT PREP

by eileen1017 Thu Mar 19, 2009 10:59 pm

nazimd73 Wrote:Hi,
Can someone help me solve this problem.

(5^21) x (4^11)= 2 x 10^n.


What is n


4^11 can also be rewritten as (2^2)^11, then 2^22 or (2^21)*2

(5^21)x(2^21)x2=2* (5x2)^21=2*10^21, hence n=21
RonPurewal
Students
 
Posts: 19744
Joined: Tue Aug 14, 2007 8:23 am
 

Re: Combining exponents from GMAT PREP

by RonPurewal Sat Mar 21, 2009 7:24 am

tricky-exponents-t1187.html
Post a reply
Return to GMAT Official Practice Test Math