Aschool employs 75 teachers. the following table summarises their length of service at the school,
classified by gender.

less than 3 years 3 years to 8 years more than 8 years
female 12 20 13
male 8 15 7

(i) find the probability that a randomly selected teacher:

(i) is female;
(ii) is female, given that the teacher has more than 8 years service.

There are

female teachers, and

male teachers.

This means that, out of a total of 75 teachers, 45 are female, leading to a probability of

of selecting a female teacher.

If we restrict to those with more than 8 years service, there are 13 female teachers and 7 male teachers.

So, out of a total of 21 teachers, there are 13 female teachers, leading to a probability of

of selecting a female teacher.

(x, y)→(x − 8, y − 7)

step-by-step explanation:

enjoy!

true !

step-by-step explanation: