The owner of a clothing store buys T-shirts for c dollars each and sells them for p dollars each. Last month she bought 600 t-shirts and sold 500
of them and made a profit of $2,800. This month she bought 400 T-shirts
and sold them all and made a profit of $2,400. Which system of equations
can be used to determine the values of cand p?
a. 500p - 600c = 2,800
600p - 500c = 2,800

b. 400p - 400c = 2,400
400p - 400C - 2,400

c. 500p - 600c = 2,800
600p - 500c = 2,800

d. 400p - C = 2,400
400p - C = 2,400