John makes $60 a week from his job. He earns a raise and now makes $90 a week. What is the % increase?  Choices.
A) 16 %  B) 50 %  C) 17 %  D) 17.61 %  E) 17.56 %

Rationale: "increase = ( 30 / 60 ) * 100 = ( 3 / 6 ) * 100 = 50 % . b"
Answer: B