Question

1. Find the sum of odd integers from 1 to 2001.
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Answer 1

hope it's used for you...

Answer 2

Answer:

required sum1+3+5+7+......+2001

the above series is an AP

here,

a=1

d=2

nth term=2001

an=a+(n-1)d

2001=1+(n-1)2

2001=1+2n-2

2001=2n-1

n=1001

hence,

the required sum

Sn =S1001=1001/2(1+2001)=1001/2×2002=(1001)^2=1002001