The Quantity of Coffee Demanded, Q^D, Depends on the Price

The quantity of coffee demanded, Q^D, depends on the price of coffee, P_c, and the price of tea, P_T. The quantity of coffee supplied, Q^S, depends on the price of coffee, P_c, and the price of electricity, P_E , according to the following equation: $$\begin{array} { l } Q ^ { D } = 17 - 2 P _ { \mathrm { c } } + 10 P _ { \mathrm { T } } \\Q ^ { \mathrm { S } } = 2 + 3 P _ { \mathrm { c } } - 5 P _ { \mathrm { E } }\end{array}$$
a. If the price of teais $\$ 1.00$ and the price of electricity is $\$ 0.50$ , what is the equilibrium price and quantity of coffee?
b. What is/are the endogenous variable(s) in this model?
c. What is/are the exogenous variable(s) in this model?