Question

find the sum of first 10 multiple of 5 by using
AP​

Answer 1

Answer:

given:

a=5

an=50

so,

sn= n/2(a+an)

=10/2(5+50)

=5*55

=275

Answer 2

Answer:

=50

5, 10, 15, 20, 25, 30, 35, 40, 45, 50 =50