 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 13x square plus 26x plus 15. Find the marginal revenue when X is equal to 7. Now let us proceed on to the solution. Given to us that Rx is equal to 13x square plus 26x plus 15 where Rx is the total revenue. Now differentiating it with respect to X we get d by dx of Rx is equal to 26x plus 26 and we have to find the marginal revenue when X is equal to 7. Now therefore d by dx of Rx at X is equal to 7 is equal to 26 multiplied by 7 plus 26 which is equal to 182 plus 26 which is equal to 208. Hence the required marginal revenue rupees 208 and this is the required answer. I hope you understood this question. Bye and have a nice day.