Study the given pattern carefully and select the number that can replace the question mark (?) in it. (NOTE : Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)
(6, 1, 18)
(5, 4, 60)
(6, 2, ?)

Correct option is A

In this question following logic is followed-
(1^st × 2^nd) × 3 = 3^rd Number
6, 1, 18 → (6 × 1) × 3 = 6 × 3 = 18
5, 4, 60 → (5 × 4) × 3 = 20 × 3 = 60
Similarly,
6, 2, ? → (6 × 2) × 3 = 12 × 3 = 15
Therefore, the correct answer is (a).