Choose the missing term out of the given alternatives:
C02T, D05S, F10Q, I17N, ?, R37E
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → M26J
In a letter-number 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 C (3), D (4), F (6), I (9): the gaps are 1, 2, 3, so the next gaps are 4 and 5: \(9+4=13\) (M), and \(13+5=18\) (R), as in R37E
Numbers 02, 05, 10, 17: each is a square plus 1 (\(1^2+1,\ 2^2+1,\ 3^2+1,\ 4^2+1\)), so the next is \(5^2+1=26\), and then \(6^2+1=37\), as in R37E
Last letters T (20), S (19), Q (17), N (14): the gaps are 1, 2, 3 going back, so the next is \(14-4=10\) (J), and then \(10-5=5\) (E), as in R37E
So the missing term is M26J.