AP EAMCET · Maths · Permutation Combination
Find the total number of rectangles on a normal chessboard.
- A \({ }^8 \mathrm{C}_2 \times{ }^8 \mathrm{C}_2\)
- B \({ }^8 \mathrm{C}_2+{ }^8 \mathrm{C}_2\)
- C \({ }^9 \mathrm{C}_2 \times{ }^9 \mathrm{C}_2\)
- D \({ }^9 P_2 \times{ }^9 P_2\)
Answer & Solution
Correct Answer
(C) \({ }^9 \mathrm{C}_2 \times{ }^9 \mathrm{C}_2\)
Step-by-step Solution
Detailed explanation
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 \(=9_{c_2} \times 9_{c_2}\) Hence, option (c) is correct.
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