50% of major airline companies equip their planes with wireless internet access. 70% of major airlines offer passengers free on-board snacks. What is the greatest possible percentage of major airline companies that offer both wireless internet and free on-board snacks?
Select the correct option:	A) 20 %	B) 30 %	C) 40 %	D) 50 %	E) 70 %

Rationale: "to maximize the percentage of companies offering both , let ' s assume that all 50 % of companies which offer wireless internet also offer snacks . the answer is d ."
Answer: D