Saw this question in an aptitude test. Tried simple multiplication & addition but couldn't find a pattern.
$$\begin{array}{|c|c|c|} \hline \ 3 & 6 & 9 \\ \hline \ 8 & 4 & 12 \\ \hline \ 4 & 2 & x \\ \hline \ 6 & 12 & 9 \\ \hline \end{array}$$
Find the value of x.
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recreational-mathematics
puzzle
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3Is this more suited for puzzling? – 2017-02-21
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0Agree with Parcly. Probably more suited for puzzling. – 2017-02-21
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1Here $x$ can be anything by making use of the interpolating polynomial; for instance, for $x=1$, consider http://m.wolframalpha.com/input/?i=interpolating+polynomial+%7B3%2C6%2C9%2C8%2C4%2C12%2C4%2C2%2C1%2C6%2C12%2C9%7D&x=7&y=7. – 2017-02-21
1 Answers
1
I suspect the trick here is to not to try to find a rule which works for the rows, but for the columns. Then one possible solution is
$12$, because $3\times8=4\times6,6\times4=2\times12,9\times12=12\times9$.