Step 1: Understanding the Concept:
The question asks to calculate "Marginal Revenue" when the input (labour) is changed. This is more accurately termed the Marginal Revenue Product of Labour (MRP\(_L\)). It measures the change in total revenue resulting from employing one additional unit of labor.
Step 2: Key Formula or Approach:
The formula for Marginal Revenue Product of Labour is:
\[ MRP_L = \frac{\text{Change in Total Revenue } (\Delta TR)}{\text{Change in Quantity of Labour } (\Delta L)} \]
Step 3: Identifying the Given Values:
\begin{itemize}
\item Initial number of labourers (\(L_1\)) = 10
\item Initial Total Revenue (\(TR_1\)) = Rs. 1,000
\item Increase in labourers = 5
\item New number of labourers (\(L_2\)) = 10 + 5 = 15
\item New Total Revenue (\(TR_2\)) = Rs. 1,500
\end{itemize}
Step 4: Calculating the Changes:
\begin{itemize}
\item Change in Total Revenue (\(\Delta TR\)) = \(TR_2 - TR_1\) = 1,500 - 1,000 = Rs. 500
\item Change in Quantity of Labour (\(\Delta L\)) = \(L_2 - L_1\) = 15 - 10 = 5 labourers
\end{itemize}
Step 5: Calculating Marginal Revenue Product:
Substituting the values into the formula:
\[ MRP_L = \frac{500}{5} = 100 \]
This means that, on average, each of the 5 additional labourers added Rs. 100 to the total revenue.
Step 6: Final Answer:
The Marginal Revenue (or more accurately, the Marginal Revenue Product per labourer) is Rs. 100.