 Hello and welcome to the session. Let us understand the following question which says, the total revenue in rupees received from the sale of X units of a product is given by Rx is equal to 3x square plus 36x plus 5. The marginal revenue when X is equal to 15 is A 116 B 96 C 90 or D 126. Now let us proceed on to the solution. It is given to us that Rx is equal to 3x square plus 36x plus 5, where Rx is the total revenue. Now differentiating Rx with respect to X we get dy dx of Rx is equal to 6x plus 36. Here we have to find the marginal revenue when X is equal to 15. Therefore dy dx of Rx at X is equal to 15 is equal to 6 multiplied by 15 plus 36, which is equal to 19 plus 36, which is equal to 126. Hence the required and the correct option is D. Therefore D is the required answer. I hope you understood this question. Bye and have a nice day.