A clock strikes once at 1 o'clock, twice at 2 o'clock, and so on. How many times will it strike in 12 hours?
Q1. A clock strikes once at 1 o'clock, twice at 2 o'clock, and so on. How many times will it strike in 12 hours?
Answer: 78
Explanation: Sum of first 12 natural numbers = n(n + 1) / 2 = 12 * 13 / 2 = 78.