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Consider a skew-symmetric matrix A = a b - b c such that a , b and c are selected from the set S = 0, 1 , 2, 3 , . . . . . . . . 12 . If A is divisible by 3 , then the number of such possible matrices is

Options

  1. A4
  2. B5
  3. C6
  4. D12

Correct answer

B. 5

Step-by-step solution

∵ A is skew symmetric ⇒ a = c = 0 A = b 2 ∵ A is divisible by 3 ⇒ b can be 0,3 , 6,9 , 12 (five possibilities)

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