Which of the following letter-number clusters will replace the question mark (?) in the given series?
POL15, ?, RSR19, SUU21, TWX23, UYA25
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. QQO17.
P + 1 = Q, Q + 1 = R, R + 1 = S, S + 1 = T, T + 1 = U
O + 2 = Q, Q + 2 = S, S + 2 = U, U + 2 = W, W + 2 = Y
L + 3 = O, O + 3 = R, R + 3 = U, U + 3 = X, X + 3 = A
15 + 2 = 17, 17 + 2 = 19, 19 + 2 = 21, 21 + 2 = 23, 23 + 2 = 25