The sum of first 45 natural numbers is:
Answer: A
The sum of the first n natural numbers is given by the formula \(S_n = \frac{n(n+1)}{2}\).
Here, n = 45.
Sum = \(\frac{45(45+1)}{2} = \frac{45 \times 46}{2} = 45 \times 23 = 1035\).