1986 AJHSME Problems/Problem 8

Revision as of 11:33, 24 January 2009 by 5849206328x (talk | contribs) (Solution)


In the product shown, $\text{B}$ is a digit. The value of $\text{B}$ is

\text{B}2 \\
\times 7\text{B} \\ \hline
6396 \\
\end{tabular}\] (Error compiling LaTeX. ! Missing $ inserted.)

$\text{(A)}\ 3 \qquad \text{(B)}\ 5 \qquad \text{(C)}\ 6 \qquad \text{(D)}\ 7 \qquad \text{(E)}\ 8$


Note that in any multiplication problem, the only 2 digits that will influence the last digit of the number will be the last digits of each number being multiplied.

So, $2 \times \text{B}$ has a units digit of $6$, so $\text{B}$ is either $3$ or $8$. If $\text{B}=3$, then the product is $32\times 73$, which is clearly too small, so $\text{B}=8$


See Also

1986 AJHSME Problems

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