UGC NET Questions (Paper – 1)

The differences between successive terms are 5, 10, 20 and 40, each approximately doubling the previous difference. If this pattern continues, the next difference should be 80. Adding 80 to the last term 79 gives 159. Therefore, 159 is the correct next term in the sequence.

Option A:
Option A is 120, which gives a difference of 41 from 79 and does not align with the expected 80. This breaks the doubling behaviour of the differences. Hence, 120 is not correct.

Option B:
Option B is 140, implying a difference of 61, which again fails to match the predicted 80. It does not continue the simple doubling rule. Therefore, 140 cannot be accepted.

Option C:
Option C equals 159 and produces the new difference 80, following 5, 10, 20 and 40 in a clear doubling pattern. The extended differences 5, 10, 20, 40, 80 make the structure consistent. Thus, 159 is the valid continuation.

Option D:
Option D is 180, giving a difference of 101 from 79. That has no relation to the doubling sequence of differences and therefore breaks the pattern. So, 180 is not suitable.

The differences are −5, −8, −11 and −14, which decrease by 3 each time. The next difference should therefore be −17. Adding −17 to the last term 12 gives 12 − 17 = −5. Hence, −5 is the correct next term in the series.

Option A:
Option A uses the new difference −17 and yields −5, keeping the second-level pattern of subtracting 3 from each successive difference. The extended sequence of differences −5, −8, −11, −14, −17 remains consistent. Thus, −5 correctly continues the series.

Option B:
Option B is 0, which would require subtracting 12 from 12, corresponding to a difference of −12. That does not follow the −5, −8, −11, −14 progression. Therefore, 0 is not correct.

Option C:
Option C is 2, which implies a difference of −10 from 12. This value does not arise from continuing the pattern of reducing differences by 3. Hence, 2 cannot be accepted.

Option D:
Option D is 4, yielding a difference of −8, which repeats an earlier step rather than moving further by −3. This breaks the steadily changing differences and is therefore not suitable.

The first-level differences are 4, 8, 12, 16 and 20. These differences form an arithmetic progression with common difference 4. Consequently the next difference should be 24. Adding 24 to 61 gives 85 as the next term in the series. This choice keeps the second-level arithmetic pattern intact and yields a smooth numerical growth.

Option A:
Option A yields a difference of 20 from 61, merely repeating the last gap instead of extending it. The sequence of differences would become 4, 8, 12, 16, 20, 20, which breaks the constant increment of 4 between gaps. Hence 81 cannot be correct.

Option B:
Option B gives a difference of 22, so the jump from 20 to 22 is only 2. This violates the established rule that each new difference must be 4 more than the previous one. Therefore 83 does not align with the underlying structure.

Option C:
Option C would produce a difference of 28, so the step from 20 to 28 is 8, not 4. This makes the progression among the differences irregular and undermines the pattern. Thus 89 is not a suitable next term.

Option D:
Option D introduces a difference of 24, continuing the sequence of gaps 4, 8, 12, 16, 20, 24. This preserves the arithmetic progression at the second level and leads to 61+24 = 85. For this reason, 85 is the correct continuation.

The first-level differences are 9, 19, 29 and 39. These differences themselves form an arithmetic sequence with common difference 10. To preserve this pattern, the next difference must be 49. Adding 49 to 102 gives 151 as the next term. Thus 151 is the only option that keeps the second-level pattern perfectly intact.

Option A:
Option A corresponds to adding 49 to 102, giving 151 and extending the differences to 9, 19, 29, 39, 49. This preserves the constant increase of 10 between successive differences. Because both the original series and the sequence of gaps remain consistent, 151 is the correct continuation.

Option B:
Option B would make the next difference 47, so the differences become 9, 19, 29, 39, 47. The jump from 39 to 47 is 8, not 10, so the second-level pattern breaks. Hence 149 does not follow the intended rule of steadily increasing differences by 10.

Option C:
Option C would require a difference of 51 from 102, giving differences 9, 19, 29, 39, 51. Here the increment from 39 to 51 is 12, which again violates the constant second-level difference of 10. Therefore 153 cannot be accepted as the next term.

Option D:
Option D implies a difference of 45 from 102, so the last increment in the difference sequence is only 6. This contradicts the observed +10 progression that generates 9, 19, 29 and 39. As a result, 147 is not a valid continuation of the series.

The differences are 7, 15 and 31. Each difference is roughly double the previous one plus 1: 7×2+1 = 15 and 15×2+1 = 31. Continuing this rule, the next difference should be 31×2+1 = 63. Adding 63 to 58 gives 121. Therefore, 121 is the correct next term in the series.

Option A:
Option A is 110, which gives a difference of 52 from 58, not matching the predicted 63. This does not follow the doubling plus one structure. Hence, 110 is not correct.

Option B:
Option B is 118, implying a difference of 60, which again fails to align with 63. It underestimates the expected growth in the differences. Therefore, 118 cannot be accepted.

Option C:
Option C equals 121, which yields the required new difference of 63. The sequence of differences 7, 15, 31, 63 shows a clear pattern where each term is nearly double the previous one plus one. This confirms 121 as the correct answer.

Option D:
Option D is 125, giving a difference of 67. That overshoots the predicted 63 and disrupts the precise doubling-plus-one rule. Thus, 125 is not suitable here.