If there are 9 horizontal lines and 9 vertical lines in a chess board, how many rectangles can be formed in the chess board? Select the correct option:  A) 1200  B) 1245  C) 1296  D) 1340  E) 1450
Number of rectangles that can be formed by using m horizontal lines and n vertical lines   = m12962 × n12962   Here m = 9, n = 9   Hence, number of rectangles that can be formed   = m12962 × n12962   = 912962 × 912962 = (912962)2   =(9×82×1)2=362=1296=(9×82×1)2=362=1296   ANSWER 1296 1296
<result>C</result>
If there are 9 horizontal lines and 9 vertical lines in a chess board, how many rectangles can be formed in the chess board?