What is the sum of all the natural numbers from 1 to 100?

The correct answer is Option (3) → 5050

The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). It comes from pairing the numbers from the two ends: 1 + 100, 2 + 99, 3 + 98, … each pair adds up to 101.

• There are 100 numbers, so there are 50 pairs

• Sum \(\displaystyle =50\times101=\frac{100\times101}{2}=5050\)