Library / CEMC Gauss (Grade 7) /52 of 462

CEMC Gauss (Grade 7), 2005

Algebra Difficulty 1.0 Junior Find the answer Canada

The symbol $\begin{array}{|c|c|}\hline 3 & 4 \\ \hline 5 & 6 \\ \hline \end{array}$ is evaluated as $3 \times 6 + 4 \times 5 = 38$ . If $\begin{array}{|c|c|}\hline 2 & 6 \\ \hline 1 & \square \\ \hline \end{array}$ is evaluated as $16$ , then the number that should be placed in the empty space is

(A) $1$ (B) $2$ (C) $3$ (D) $4$ (E) $5$

We don't reproduce this publisher's solutions. Their own solution is here — work the problem first.

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.