# Problem with the discrete demand curve

I am starting to learn microeconomics from a book named Intermediate Microeconomics by Hal R. Varian. The first chapter is on market. I was attempting to solve the end text problems but was stuck. Following are the two problems. For question number 1, I made the following demand curve: The solid blue line in the graph shows that if the price lies between 200 and 500 then the demand is constant at 25. And accordingly, I attempted question number 2 and thought that for 24 apartments there will be no equilibrium price since there is no intersection between the demand curve and supply curve. But the equilibrium price for the same is given to be 500. So I searched online and got the following curve: Please help me understand what is wrong with my graph and why the above graph is correct. Kindly correct me if I am wrong, according to the above graph we can conclude that at a price of 400 there is no demand and at the price of 500 the demand is not fixed at a constant number but is changing.