Question

calculate the sum of 10 th term of the ap if a= l and d = 2​

Answer 1

given a=1,d=2,An=10

sum of terms in ap formula is Sn= n/2(2a+(n-1)d)

=> Sn= 10/2(2(1)+(10-1)2)

= 5((2+18))

= 5(20)

=5(20)

Sn = 100

therefore the sum of 10 terms of ap is 100