The price of lunch for 15 people was $211.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity?  Pick:
A) $ 11.73  B) $ 12.78  C) $ 13.80  D) $ 14.00  E) $ 15.87

Rationale: "take the initial price before the gratuity is 100 the gratuity is calculated on the final price , so as we assumed the final bill before adding gratuity is 100 so gratuity is 15 % of 100 is 15 so the total price of meals is 115 so the given amount i . e 211 is for 115 then we have to calculate for 100 for 115 211 for 100 x so by cross multiplication we get 115 x = 100 * 211 = > x = 100 * 211 / 110 by simplifying we get x as 191.81 which is the price of lunch before gratuity so the gratuity is 19.19 so as the question ask the average price person excluding gratuity is 191.81 / 15 = 12.78 so our answer is b )"
Answer: B