exponents.

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exponents.

by anjaligeorge1 » Wed Jan 07, 2009 9:42 am
Is x > k?
(1) 2^x • 2^k = 4
(2) 9^x • 3^k = 81

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by amitabhprasad » Wed Jan 07, 2009 10:11 am
I am getting "C".
Stmt1;
2^x • 2^k = 4 ==> 2^x • 2^k = 2^2
==> x+ k = 2 insufficient
Stmt 2;

9^x • 3^k = 81 ==> 3^2x.3^k = 3^4
2x+k = 4 --> insufficient
from 1 and 2 ==> x = 2 and k = 0 hence sufficient.

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by mental » Wed Jan 07, 2009 10:15 am
I am getting C
Maybe I am missing something

Assumption . means multiplication!!!

st1: equate both the sides to the base of 2, the powers should be equal
so, x + k = 2, no info on x and k, insufficient

st2: equate both the sides to the base of 3, the powers should be equal
so, 2x + k = 4, no info on x and k, insufficient

Together: 2 variables, 2 equations: SUFFICIENT

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by maihuna » Wed Jan 07, 2009 10:33 am
1: x+k = 2
2: 2x+k = 4

It can be solved for individual x k values. C

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by vivek.kapoor83 » Wed Jan 07, 2009 11:22 am
same as above C
oa?

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by cramya » Wed Jan 07, 2009 5:33 pm
OA is C) if I am not mistaken. Will wait for the user to confirm though.

Good job guys!