Which term will replace the question mark (?) in the following series?
C27, E16, G125, I36, ?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → K343
In a letter-number series the letters and the numbers follow separate rules, so each part is checked on its own.
Letters C (3), E (5), G (7), I (9): 2 places ahead each time, so the next letter is \(9+2=11\), that is K
Numbers: \(27=3^3\), \(16=4^2\), \(125=5^3\), \(36=6^2\), so the bases go 3, 4, 5, 6 and the powers cube and square in turn
The next base is 7 with a cube: \(7^3=343\)
So the missing term is K343.