Question

Find the sum of first 10 odd formal number​

Answer 1

Answer:

100

Step-by-step explanation:

1+3+5+7+9+11+13+15+17+19 = 100

Answer 2

Answer:

first odd number(a)=1

common difference between two odd numbers(d) = 2

numbers of terms(n) = 10

So,

the sum of first 10 odd formal number​ = n/2(2a + (n-1)d)

                                                               =10/2((2×1)+(10-1)2)

=5×(2+9×2)

=5×(20)

=100

the sum of first 10 odd formal number​ = 100