Suppose That the Supply of Apples Can Be Represented by the Following

Suppose that the supply of apples can be represented by the following equation: $Q ^ { s } = 2 P + 500$ . Further suppose that the demand for apples can be represented by the following equation: $Q d =$ $900 - 3 P$ . Which of the following is the equilibrium price in the market for apples?

A) 10
B) 50
C) 80
D) 100