Difference between revisions of "1987 AJHSME Problems/Problem 3"
5849206328x (talk | contribs) (New page: ==Problem== <math>2(81+83+85+87+89+91+93+95+97+99)=</math> <math>\text{(A)}\ 1600 \qquad \text{(B)}\ 1650 \qquad \text{(C)}\ 1700 \qquad \text{(D)}\ 1750 \qquad \text{(E)}\ 1800</math> ...) |
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==Solution== | ==Solution== | ||
| − | {{ | + | <math>2(81+83+85+87+89+91+93+95+97+99)</math> |
| + | |||
| + | <math>\begin{align*} | ||
| + | & = 2\Big( (81+99) + (83+97) + (85+95) + (87+93) + (89+91) \Big) \\ | ||
| + | & = 2(180+180+180+180+180) \\ | ||
| + | & = 2\cdot 5\cdot 180 \\ | ||
| + | & = \boxed{1800}. | ||
| + | \end{align*}</math> | ||
==See Also== | ==See Also== | ||
[[1987 AJHSME Problems]] | [[1987 AJHSME Problems]] | ||
Revision as of 14:47, 29 January 2009
Problem
Solution
$\begin{align*} & = 2\Big( (81+99) + (83+97) + (85+95) + (87+93) + (89+91) \Big) \\ & = 2(180+180+180+180+180) \\ & = 2\cdot 5\cdot 180 \\ & = \boxed{1800}. \end{align*}$ (Error compiling LaTeX. Unknown error_msg)
