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1991 AJHSME Problems/Problem 12

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Problem

If \frac{2+3+4}{3}=\frac{1990+1991+1992}{N}, then N=

\text{(A)}\ 3 \qquad \text{(B)}\ 6 \qquad \text{(C)}\ 1990 \qquad \text{(D)}\ 1991 \qquad \text{(E)}\ 1992

Solution

Note that for all integers n\neq 0, \frac{(n-1)+n+(n+1)}{n}=3. Thus, we must have N=1991\rightarrow \boxed{\text{D}}.

See Also

1991 AJHSME (ProblemsResources)
Preceded by
Problem 11
Followed by
Problem 13
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
Looking for a challenging algebra text? Preparing for MATHCOUNTS or the AMC exams?
Check out Art of Problem Solving's Introduction to Algebra by Richard Rusczyk.
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