Directions: Find out the wrong number in each sequence 125, 127, 130, 135, 142, 153, 165

### Concept & Logic Investigate the differences between successive terms to identify an underlying pattern. ### Step-by-Step Solution Let's compute the differences: - $127 - 125 = 2$ - $130 - 127 = 3$ - $135 - 130 = 5$ - $142 - 135 = 7$ - $153 - 142 = 11$ The sequence of differences is 2, 3, 5, 7, 11... These are consecutive prime numbers. The next prime number after 11 is 13. So, the next term should be $153 + 13 = 166$. The given term is 165, which is incorrect. ### Exam Strategy & Shortcut Recognizing the sequence of prime numbers (2, 3, 5, 7, 11...) is crucial for many series questions. When differences are small, always check if they form a prime number series. ### Common Pitfall Mistaking the differences for a pattern of odd numbers (3, 5, 7, 9...) and assuming the next difference should be 9. The presence of 2 at the beginning and 11 later confirms it's a prime number series, not just odd numbers. ### Final Answer Therefore, the correct answer is **165**.