Question

A bag contains three black balls, four white balls and five red balls. Three balls are removed without replacement. What is the probability of obtaining
a one of each colour
b at least two red balls ?

Answer 1

A comittee consist of 6 men and 4 women. A subcomittee is made by randomly choosing three of the comittee members. What is the probability that
a they are all women
b two of them are men?

Answer 2

10 balls at start

1 prob black, white, red
= 3/10 * 4/9 * 5/8

2 prob black, red, white
= 3/10 * 5/9 * 4/8 same as above

3 prob white, black, red
= 4/10 * 3/9 * 5/8 same again

4 prob white, red , black
same

5 prob red , white, black
same

6 prob red, black, white
same

so
6 * 3/10 * 4/9 * 5/8

Answer 3

Try the rest now.