Question

In the given calander, the difference between the product of the diagonal numbers taken for any four numbers forming a square is equal to

$\begin{array}{ccc}6& 8& 10\\ 9& 12& 15\\ 12& 16& 20\end{array}$

• A. 0
• B. 12
• C. 6
• D. 4

Answer 1

The correct option is A

0

$\begin{array}{ccc}6& 8& 10\\ 9& 12& 15\\ 12& 16& 20\end{array}$

Consider the four numbers $\begin{array}{cc}& \\ 6& 8\\ 9& 12\end{array}$ forming a square.

$12\times 6-9\times 8$

$=72-72$

$=0$

Consider the four numbers $\begin{array}{cc}& \\ 12& 15\\ 16& 20\end{array}$ forming a square.

The difference is

$12\times 20-16\times 15$

$=240-240$

$=0$

Similarly, for any four numbers forming a square, the difference is a constant and is equal to 0.