Find the next term in the alpha-numeric series:
Z3A, W7E, T15I, Q31M, N63Q, ?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → K127U
In an alpha-numeric series, each part of the term follows its own rule, so the first letters, the numbers and the last letters are checked separately.
First letters (each is 3 places back):
Z (26), W (23), T (20), Q (17), N (14)
The next is 14 − 3 = 11, that is, K
Numbers (each is double the previous one plus 1):
3, 7, 15, 31, 63 (\(3\times2+1=7\), \(7\times2+1=15\), …)
The next is \(63\times2+1=\) 127
Last letters (each is 4 places ahead):
A (1), E (5), I (9), M (13), Q (17)
The next is 17 + 4 = 21, that is, U