Tim has two bags of marbles, A and B.
Bag A contains 8 white, 4 red and 3 yellow marbles.
Bag B contains 6 white, 7 red and 2 yellow marbles.
Tim also has an ordinary fair 6-sided dice. He rolls the dice. If he obtains a 1 or 2, he chooses two marbles at random from bag A, without replacement. If he obtains a 3, 4, 5 or 6, he chooses two marbles at random from bag B, without replacement.
Find the probability that both marbles are white.
In a group of students, the numbers of boys and girls studying Art, Music and Drama are given in the following table. Each of these 160 students is studying exactly one of these subjects.
| Art | Music | Drama | |
|---|---|---|---|
| Boys | 24 | 40 | 32 |
| Girls | 15 | 12 | 37 |
Three students are chosen at random. Find the probability that exactly 1 is studying Music and exactly 2 are boys.
A biased die has faces numbered 1 to 6. The probabilities of the die landing on 1, 3 or 5 are each equal to 0.1. The probabilities of the die landing on 2 or 4 are each equal to 0.2. The die is thrown twice. Find the probability that the sum of the numbers it lands on is 9.
Two identical biased triangular spinners with sides marked 1, 2 and 3 are spun. For each spinner, the probabilities of landing on the sides marked 1, 2 and 3 are \(p\), \(q\) and \(r\) respectively. The score is the sum of the numbers on the sides on which the spinners land. You are given that \(P(\text{score is } 6) = \frac{1}{36}\) and \(P(\text{score is } 5) = \frac{1}{9}\). Find the values of \(p, q\) and \(r\).
A bag contains 10 pink balloons, 9 yellow balloons, 12 green balloons and 9 white balloons. 7 balloons are selected at random without replacement. Find the probability that exactly 3 of them are green.