Complete the series: 1, 3, 7, 15, ?
Question 1
Q1. Complete the series: 1, 3, 7, 15, ?
Answer: 31
Explanation: The series is formed by subtracting 1 from the next power of 2: 2^1 - 1 = 1, 2² - 1 = 3, 2³ - 1 = 7, 2⁴ - 1 = 15, 2^5 - 1 = 31.