Question

1+3+5+9..........+99 =

• A. 10000
• B. 2500
• C. 9801
• D. 4950

Answer 1

Answer:

B. 2500

$1+2+3+..+n = n^2$

$n=\frac{99+1}{2}=50$

$1+2+3+....99 =50^2= 2500$