A board has 16 squares as shown in the figure (a $4 \times 4$ grid of squares). Out of these 16 squares, two squares are chosen at random. The probability that they have no side in common is : (1) $7/10$ (2) $4/5$ (3) $23/30$ (4) $3/5$
A board has 16 squares as shown in the figure (a $4 \times 4$ grid of squares). Out of these 16 squares, two squares are chosen at random. The probability that they have no side in common is :\\
(1) $7/10$\\
(2) $4/5$\\
(3) $23/30$\\
(4) $3/5$