Question

1+3+5+7+..............+17 is equal to​

Answer 1

Answer:

1+3+5+7+............+17

a=1,d=2,n=17,Sn=?

since,an=a+(n-1)d

1+(17-1)2

1+32

33

Now,Sn =n/2(a+an)

17/2(1+33)

17/2*34

17*17=289