In the number series 20, 17, 14, 11, the next term is _______. – UGC NET Question

Successive terms decrease by 3: 17 − 20 = −3, 14 − 17 = −3 and 11 − 14 = −3. This forms an arithmetic progression with common difference −3. Subtracting 3 from the last term 11 gives 8. Therefore, 8 is the next term in the series.

Option A:
Option A keeps the same step because 11 − 3 = 8, maintaining the constant change of −3. The series 20, 17, 14, 11, 8 stays perfectly regular under this rule. Hence, this option correctly extends the pattern.

Option B:
Option B is 10, which is only 1 less than 11 and would change the difference to −1. That conflicts with the consistent decrease by 3 observed earlier. Therefore, 10 cannot be accepted.

Option C:
Option C is 9, giving a difference of −2 from 11 and again disturbing the established constant difference. The sequence would become irregular at the end. Thus, 9 is not correct.

Option D:
Option D is 7, which is 4 less than 11, producing a difference of −4. This also contradicts the steady difference of −3 that defines the progression. Therefore, 7 is not the right choice.