Exams › SSC CGL (Prelims) › General

Find the incorrect number in the series: 3, 7, 15, 31, 63, 127, 250

1. 63
2. 127
3. 250
4. 31

Correct answer: 250

Solution

The series follows the pattern 3, 7, 15, 31, 63, 127, which are all of the form $2^n-1$. The next term should be 255, not 250, so 250 is incorrect.

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