Consider the Following Demand and Supply Curves $Q ^ { \mathrm { d } } = 100 - 2 \mathrm { P }$

Multiple Choice

Consider the following demand and supply curves: $Q ^ { \mathrm { d } } = 100 - 2 \mathrm { P }$ , and $\mathrm { Q } ^ { s } = 1 / 2 \mathrm { P }$ , calculate the equilibrium $P$ and $Q$ for this initial situation and assuming the supply curve changes to $Q ^ { s } = 1 / 2 P$ $+ 10$ . Which of the following is correct?

A) the initial equilibrium is $P = 40 , Q = 20$ and the supply curve shifts left.
B) the initial equilibrium is $P = 40 , Q = 20$ and the new equilibrium is $P = 36 , Q = 28$ .
C) the initial equilibrium is $\mathrm { P } = 40 , \mathrm { Q } = 20$ and the new equilibrium remains the same.
D) the initial equilibrium is $P = 40 , Q = 20$ and the new equilibrium is $P = 38 , Q = 28$ .