[tex]P.A(2,4,6,8,...,450)[/tex]
[tex]a_{1}=2[/tex]
[tex]a_{2}=4[/tex]
[tex]q = a_{2} - a_{1} = 4 - 2 = 2[/tex]
[tex]a_{n} = a_{1} + (n - 1)r[/tex]
[tex]450 = 2 + (n - 1)2[/tex]
[tex]450 = 2(1 + n - 1)[/tex]
[tex]450 = 2n[/tex]
[tex]450/2=n[/tex]
[tex]n = 225[/tex]
[tex]S_{n}=(a_{1}+a_{n})*n/2[/tex]
[tex]S_{225}=(a_{1}+a_{225})*225/2[/tex]
[tex]S_{225}=(2+450)*225/2[/tex]
[tex]S_{225}=452*225/2[/tex]
[tex]S_{225}=226*225[/tex]
[tex]S_{225}=50850[/tex]