A local university found it could classify its students into

A local university found it could classify its students into one of three general categories: morning students (40%), afternoon students (29%), and evening students. 38% of the morning students, 22% of the afternoon students, and 26% of the evening students live on campus.

What is the probability a non-morning student does not live on campus?

Solution

Say totally we have 1000 students

Moring = 40% = 400
Afternoon = 290
Evening = 310

38% of morning = 152 in campus
22% of afternoon = 22% of 290 = 63.8 in campus
So, 290 - 63.8 = 226.2 ---> afternoon not in campus
26% of evening = 0.26 * 310 = 80.6 in campus
So, 310 - 80.6 = 229.4 --> evening not in campus

P(non morning not in campus) = (non morning not in campus) / total non morning
(226.2 + 229.4) / (290 + 310)

1139/1500 ---> ANSWER