1998 AHSME Problems/Problem 5

Revision as of 15:45, 6 June 2011 by Minsoens (talk | contribs)

Problem 5

If $2^{1998}-2^{1997}-2^{1996}+2^{1995} = k \cdot 2^{1995},$ what is the value of $k$?

$\mathrm{(A) \ } 1 \qquad \mathrm{(B) \ } 2 \qquad \mathrm{(C) \ } 3 \qquad \mathrm{(D) \ } 4 \qquad \mathrm{(E) \ } 5$

Solution

$2^{1998} - 2^{1997} - 2^{1996} = 2^{1996}$. $2^{1996} + 2^{1995} = 2^{1995}(2 + 1) = 3 \cdot 2^{1995}$. So, the answer is $\text{(C)}.$

See also

1998 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
All AHSME Problems and Solutions