In the number series 3, 10, 21, 36, 55, the next term is _______. – UGC NET Question

The differences between terms are 7, 11, 15 and 19, each increasing by 4. The next difference should therefore be 23. Adding 23 to the last term 55 gives 78. Thus, 78 is the correct next term that extends the pattern of differences.

Option A:
Option A is 75, which gives a difference of 20 from 55. This does not follow the expected increase from 19 to 23. Therefore, 75 is inconsistent with the second-level pattern.

Option B:
Option B equals 78, yielding the required difference of 23. The extended sequence of differences 7, 11, 15, 19, 23 keeps the +4 rule intact. This makes 78 the valid continuation of the series.

Option C:
Option C is 80, which would create a difference of 25 from 55. That skips beyond 23 and breaks the steady increment of 4 in the differences. Hence, 80 is not appropriate.

Option D:
Option D is 82, giving a difference of 27, even further away from the expected 23. This choice would make the pattern irregular and unclear. Therefore, 82 cannot be accepted.