Question

The total revenue in Rupees received from the sale of $x$ units of a product is given by $R(x)=3x^2+36x+5$.The marginal revenue, when $x=15$ is

• A. 116
• B. 96
• C. 90
• D. 126

Answer 1

Answer: (D)

126

Answer 2

The correct answer D:Rs 126
Marginal revenue is the rate of change of total revenue with respect to the number of units sold.
$∴Marginal\space Revenue (MR)=\frac{dR}{dx}=3(2x)+36=6x+36$
$∴When\space x = 15,$
$MR = 6(15) + 36 = 90 + 36 = 126$
Hence, the required marginal revenue is Rs 126.