Ruben is a travel agent. He intends to sell his customers a special round-trip airline ticket package. He is able to purchase the package from the airline for $150 each. The round-trip tickets will be sold for $240 each and the airline intends to reimburse Ruben for any unsold ticket packages. Fixed costs include $5,100 in advertising costs. What is the contribution margin per ticket package? $90 $240 $390 $150