Ivan throws three fair dice.
The probability that a student at a large music college plays in the band is 0.6. For a student who plays in the band, the probability that she also sings in the choir is 0.3. For a student who does not play in the band, the probability that she sings in the choir is x. The probability that a randomly chosen student from the college does not sing in the choir is 0.58.
(a) Find the value of x.
Two students from the college are chosen at random.
(b) Find the probability that both students play in the band and both sing in the choir.
A total of 500 students were asked which one of four colleges they attended and whether they preferred soccer or hockey. The numbers of students in each category are shown in the following table.
| Soccer | Hockey | Total | |
|---|---|---|---|
| Amos | 54 | 32 | 86 |
| Benn | 84 | 72 | 156 |
| Canton | 22 | 56 | 78 |
| Devar | 120 | 60 | 180 |
| Total | 280 | 220 | 500 |
Find the probability that a randomly chosen student is at Canton college and prefers hockey.
When Shona goes to college she either catches the bus with probability 0.8 or she cycles with probability 0.2. If she catches the bus, the probability that she is late is 0.4. If she cycles, the probability that she is late is x. The probability that Shona is not late for college on a randomly chosen day is 0.63. Find the value of x.
Jameel has 5 plums and 3 apricots in a box. Rosa has x plums and 6 apricots in a box. One fruit is chosen at random from Jameel’s box and one fruit is chosen at random from Rosa’s box. The probability that both fruits chosen are plums is \(\frac{1}{4}\). Write down an equation in x and hence find x.