In a company of 160 employees, 90 are females. A total of 80 employees have advanced degrees and the rest have a college degree only. If 40 employees are males with college degree only, how many employees are females with advanced degrees? Choose the correct choice.
A) 40 B) 45 C) 50 D) 55 E) 60

Rationale: "the number of males is 160 - 90 = 70 . the number of males with advanced degrees is 70 - 40 = 30 . the number of females with advanced degrees is 80 - 30 = 50 . the answer is c ."
Answer: C