RRB NTPC · Question 95
Select the number from among the given options that can replace the question mark (?) in the following series. 13, 23, 43, 53, 73, 83, 103, 113, 133, 143, ?
Show answer & explanation
Answer: (B) 163
Explanation
The terms increase alternately by 10 and 20: 13, 23, 43, 53, 73, 83, 103, 113, 133, 143, so the next is 143 + 20 = 163.