The total revenue received from the sale of x units of a product is given by $R(X)=36x+3x^2+5  $then sum of marginal and average revenue when $x= 5$ is

118

The correct answer is option (3) → 118

The total Revenue, $R(x)$ is

$R(x)=36x+3x^2+5$

Marginal Revenue, $MR=\frac{d}{dx}R(x)$

$=\frac{d}{dx}(36x+3x^2+5)$

$=36+6x$

Average Revenue, $AR=\frac{R(x)}{x}$

$=36+3x+\frac{5}{x}$

$AR(5)=36+3(5)+\frac{5}{3}=52$

$MR(5)=36+6××5=66$

$AR+MR=52+66=118$