Difference between revisions of "1987 AHSME Problems/Problem 4"

(Created page with "==Problem== <math>\frac{2^1+2^0+2^{-1}}{2^{-2}+2^{-3}+2^{-4}}</math> equals <math>\text{(A)} \ 6 \qquad \text{(B)} \ 8 \qquad \text{(C)} \ \frac{31}{2} \qquad \text{(D)} \ 2...")
 
(Added a solution with explanation)
 
Line 6: Line 6:
 
\text{(C)} \ \frac{31}{2} \qquad  
 
\text{(C)} \ \frac{31}{2} \qquad  
 
\text{(D)} \ 24 \qquad  
 
\text{(D)} \ 24 \qquad  
\text{(E)} \ 512  </math>  
+
\text{(E)} \ 512  </math>  
 +
 
 +
== Solution ==
 +
We can factorise to give <math>\frac{2^1 + 2^0 + 2^{-1}}{2^{-3}(2^1 + 2^0 + 2^{-1})} = \frac{1}{2^{-3}} = 8</math>, which is <math>\boxed{\text{B}}</math>.
  
 
== See also ==
 
== See also ==

Latest revision as of 11:21, 1 March 2018

Problem

$\frac{2^1+2^0+2^{-1}}{2^{-2}+2^{-3}+2^{-4}}$ equals

$\text{(A)} \ 6 \qquad  \text{(B)} \ 8 \qquad  \text{(C)} \ \frac{31}{2} \qquad  \text{(D)} \ 24 \qquad  \text{(E)} \ 512$

Solution

We can factorise to give $\frac{2^1 + 2^0 + 2^{-1}}{2^{-3}(2^1 + 2^0 + 2^{-1})} = \frac{1}{2^{-3}} = 8$, which is $\boxed{\text{B}}$.

See also

1987 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 3
Followed by
Problem 5
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

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