Question

without adding find the sum of 1 + 3 + 5+7 + 9 + 11 + 13 + 15 + 19​

Answer 1

Answer:

Assuming your question was 1+3+5+7+9+11+13+15+17+19

Since this is a A.P,

Sn = n(a+l)/2

=10(1+19)/2

=10×20/2

=100

Hope it helps you