The cost of a cricket ball is Rs 500. If the price remains constant, its marginal revenue in Rs will be:

Revenue $R(x)=p\times x$, where $p$ is the price per unit and $x$ is the quantity sold.Given $p=500$ (constant).$R(x)=500x$.Marginal Revenue ($MR$) $=\frac{dR}{dx}=500$.When price is constant, marginal revenue equals the price of the unit.