Choose the missing terms out of given alternatives:
A3, E4, I10, O33, U136, ?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A685
Each term has two parts, and each part follows its own rule.
The letters are the vowels in order: A, E, I, O, U, and then back to A.
The numbers: each number is the one before it multiplied by 1, 2, 3, … in turn, with the same number added:
\(3\times1+1=4\)
\(4\times2+2=10\)
\(10\times3+3=33\)
\(33\times4+4=136\)
\(136\times5+5=685\)
So the next term is A685.