一道统计学的英文题

题目

一道统计学的英文题
it was found that 35% of all customers order hot meals and that 50% of all customers are students.Further,25% of all customers who are students order hot meals.
what is the probability that a chosen customer both does not order a hot meal and is not a student?
875

答案

Note that "Further, 25% of all customers who are students order hot meals"===> About (50% * 25%) of all customers both are students and order hot meals.===> Probability of A customer = not student &...