The following shows the demands and marginal revenue in two markets (D1 and MR1, and D2 and MR2) for a price discriminating firm along with total demand, DT, marginal revenue, MRT, and marginal cost MC.

450 D2 400 MR2 MC 350 300 DT D1 . . . . . .... ........ MRT 250 MR1 . . .......................... 200 . . . . .......... . 150 . . .................................. MC 100 50 0 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 . . D1 - - - MR1 - . - D2 - - MR2 ......... MRT DT MC