Marginal Revenue

Hi!

I've been stuck on this question for the last hour... I just can't seem to figure it out.

The problem consists of 3 parts: A, B, C.
I've managed to figure out part A, but not B and C.

Please see the attached image!

Thank you for looking!

this is the marginal revenue function, the derivative of the total revenue function

you need to sub in the value of 10 for m in the first function to get a value of q which you sub into the MR function.

for (c), redefine the total revenue function in terms of m and differentiate it w.r.t m to get the MRP function. the answer should follow after that.
hope that helps.