Question

1+2+3+4+...... sum of first 25 natural integer is​

Answer 1

Step-by-step explanation:

There's a formula for sum of first n natural numbers

n(n+1)/2

sum=25(25+1)/2

sum=25(26)/2

sum=650/2

Sun=325

Answer 2

Answer:

a=1

d=1

n=25

Sn=25/2(2+24*1)

=25/2*26

=25*13

=325