Question

1+3+5+----------------------+199​

Answer 1

Step-by-step explanation:

1+3+5+7+9+.........+199

$n \div 2 \times (2a + (n - 1) \times d)$

here n= no.of terms be added =100

a= first term =1

d= common difference= (3-1)=2

sub in formula

=100/2 (2*1 +(100-1)*2)

=50(2+(99*2))

=50(2+198)

=50(200)

=10000