| View previous topic :: View next topic |
| Author |
Message |
Atult718
Rising GMAT Star
Joined: 14 Mar 2007
Posts: 38
Thanks given: 0
Thanked 0 times in 0 posts
|
 Posted: Fri Jul 13, 2007 3:30 am Post subject: What is the simplest way to tacke this ques? |
 |
|
Hey guys,
How would you tackle this problem
5^21 x 4^11 = 2 x 10^n |
|
| Back to top |
|
 |
|
|
gabriel
Managing Director
Joined: 20 Dec 2006
Posts: 865
Thanks given: 118
Thanked 27 times in 26 posts
Location: India
|
| Posted: Fri Jul 13, 2007 4:49 am Post subject: Re: What is the simplest way to tacke this ques? |
|
|
| Atult718 wrote: | Hey guys,
How would you tackle this problem
5^21 x 4^11 = 2 x 10^n |
remember (x*y)^n = x^n*y^n ...
so 10^n=(2*5)^n = 2^n*5^n ...
also 4^11 = (2^2)^11 = 2^22 ..
So ... we have 5^21*2^22= 2 * 2^n*5^n .. that is 5^21*2^21= 2^n*5^n .. comparing the power on both the sides of the equation we get n = 21 ... |
|
| Back to top |
|
|
Atult718
Rising GMAT Star
Joined: 14 Mar 2007
Posts: 38
Thanks given: 0
Thanked 0 times in 0 posts
|
| Posted: Fri Jul 13, 2007 6:06 am Post subject: |
|
|
| thanks for the great explanation gabriel. |
|
| Back to top |
|
|
|
