Question

find sum of AP 63,65,67...........101​

Answer 1

63,65,67.....101

a=63

d=65-63=2

an= 101

an= a+(n-1) × d

101= 63+(n-1) × 2

101-63 = (n-1) × 2

38 = (n-1) × 2

(n-1)= 38/2

(n-1)= 19

n=19+1

n=20

Now,

Sn= n/2 + (a+l)

= 20/2+ (63+101)

= 10+164

=174

Hence, Proved

= 174