Option (a) is correct

1, 4, 3, 5, 6, 9, 13, 20, 31 ––––

Here the pattern is:- (first term + second term) –2 , (second term + third term) –2 and so on-

1 + 4 – 2 = 3

3 + 4 – 2 = 5

3 + 5 – 2 = 6

5 + 6 – 2 = 9

6 + 9 – 2 = 13

9 + 13 – 2 = 20

13 + 20 – 2 = 31

20 + 31 – 2 = 49

विकल्प (a) सही है

1, 4, 3, 5, 6, 9, 13, 20, 31 ––––

यहां पैटर्न है: - (पहला पद + दूसरा पद) –2, (दूसरा पद + तीसरा पद) –2

और इसी तरह-

1 + 4 – 2 = 3

3 + 4 – 2 = 5

3 + 5 – 2 = 6

5 + 6 – 2 = 9

6 + 9 – 2 = 13

9 + 13 – 2 = 20

13 + 20 – 2 = 31

20 + 31 – 2 = 49