The top three prices for works of art sold at auction in 2013 totaled $306.7 million. These three works of art were a sculpture,
a painting, and a photograph. The selling price of the painting was $50.5 million more than that of the photograph. Together, the painting and the photograph sold for $17.1 million more than the
sculpture. What was the selling price of each work?
Number of ways of picking a smaller number out of a bigger number is called combination. Number of way of picking 3 stamps out of 4 is 4C3 (4 combination 3) = 4! / (3! x (4 - 3)!) = 4! / (3! x 1!) = (4 x 3 x 2 x 1) / (3 x 2 x 1 x 1) = 24 / 6 = 4 ways.