The wages earned by Robin is 30% more than that earned by Erica. The wages earned by Charles is 70% more than that earned by Erica. How much percent is the wages earned by Charles more than that earned by Robin?
Choose the correct choice from the following options:
A) 18.75 %  B) 23 %  C) 30 %  D) 31 %  E) 100 %

Rationale: "let wage of erica = 10 wage of robin = 1.3 * 10 = 13 wage of charles = 1.7 * 10 = 17 percentage by which wage earned by charles is more than that earned by robin = ( 17 - 13 ) / 13 * 100 % = 4 / 13 * 100 % = 31 % answer d"
Answer: D