Question

witout adding find 1+3+5+7+9+11+13+15+17+19​

Answer 1

Answer:

the sets of no. are in AP

a=1 d=2 n=10

Sn=n/2(2a+(n-1)d)

so S10=10/2(2×1 +(10-1)2)

therefore S10=100

hence the sum is 100