Question

1+3+5+7+...........+2001 Sn=?​

Answer 1

a= 1

d = 2

last term = 2001

an= a+(n-1)d

2001 = 1 + 2n - 2

n =1001

Sn = 1001/2(1+2001)

= 1001×1001

Calculate and you will get the answer hope it helped you