a survey reveals that the average income of a company ’ s customers is $ 45000 per year . if 50 customers respond to the survey and the average income of the wealthiest 10 of those customers is $ 55000 , what is the average income of the other 40 customers ? is there a way to solve this using weighted average concept instead of doing tedious calculations ?	Choices.
A) $ 27,500 B) $ 35,000 C) $ 37,500 D) $ 42,500 E) $ 50,000

Rationale: let x be the average of 40 customers 40 * x + 10 * 55000 = 50 * 45000 solving this we have x = 42500 answer is d .
Answer: D