Question

Find the maximum value of the sum of the A.P. $30,27,24,21,\dots \dots$

Answer 1

Answer: 165.00

Let $I_n=0$
$30+(n-1)(-3)=0$
$n-1=10$
$n=11$
Sum is max if $n=11$
Max sum $=\frac{11}{2}[30]$
$=\frac{330}{2}=165$