In the series given below, one number is wrong. Find the wrong number.
13, 22, 31, 41, 49, 58, 67
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 41
Most steps are +9, so check each term against the rule add 9 each time:
\(13+9=22\), \(22+9=31\)
\(31+9=40\), but the series has 41
\(40+9=49\), \(49+9=58\), \(58+9=67\)
All the other terms fit if the fourth term is 40. So 41 is the wrong number.