• # question_answer Direction: Find the missing number/alphabet. 5 5 2 2 4 1 8 3 10 40 30 ? A) 10 B) 12 C) 13 D) 20 E) None of these

Explanation Option (a) is correct. In the first column, $\frac{5\times 2\times 8}{2}=40$ In the second column, $\frac{5\times 4\times 3}{2}=30$ $\therefore$ Missing number = $\frac{2\times 1\times 10}{2}=10$