Harvey has the following utility function for carrots and radishes U = c^0.4 * r^0.6 where c is the quantity of carrots consumed and r is the quantity of radishes. His marginal rate of substitution is therefore -2r/3c.Derive Harvey's demand for radishes. In this question we are attempting to calculate in terms of r. My teacher had given the solution r = 3M / 5Pr (where Pr is the price of radishes). I am lost on how this was obtained. He provided steps on how he got there but it jumps around and I cannot follow it.