1 + 2 + 3 + . . . . . . . + 98 + 99 + 100 = ?

A 5000

B 5050

C 10000

D 2500

Correct Answer: Option B

আমরা জানি,
1 + 2 + 3 + ......... + n = n(n + 1)/2

1 + 2 + 3 + ........ + 98 + 99 + 100 = 100(100 + 1)/2
= (100 × 101)/2
= 5050