Question

Find the total number o $f$ rectangles on a normal chessboard.

• A. ${ }^{8} C_{2} \times{ }^{8} C_{2}$
• B. ${ }^{8} C _{2}+8 C _{2}$
• C. ${ }^{9} C_{2} \times{ }^{9} C_{2}$
• D. ${ }^{9} P_{2} \times{ }^{9} P_{2}$

Answer 1

Answer: (C)

Total number of Rectangles in $n \times n$ chess board
$=n+1_{C_{2}} \times n+1_{C_{2}}$
$\therefore $ Total Number of Rectangles in $8 \times 8$ chess Boord
$=9_{C_{2}} \times 9_{C_{2}}$