Thank you for the opportunity to help you with your question!
here, MP and MQ are equilibrium price and quantity respectively. Also, for having no excess capacity, production is done at the minimum of average total cost curve as excess capacity =MR-MC. And mark up as written is the difference between MRP and Cost.Please let me know if you need any clarification. I'm always happy to answer your questions.
Dec 19th, 2015
MQ is 125 and MP is 450. I forgot to label in the diagram.