The probability that the school bus is on time on any particular day is 0.6. If the bus is on time the probability that Sam the driver gets a cup of coffee is 0.9. If the bus is not on time the probability that Sam gets a cup of coffee is 0.3.
(i) Find the probability that Sam gets a cup of coffee.
(ii) Given that Sam does not get a cup of coffee, find the probability that the bus is not on time.
In a certain town, 35% of the people take a holiday abroad and 65% take a holiday in their own country. Of those going abroad 80% go to the seaside, 15% go camping and 5% take a city break. Of those taking a holiday in their own country, 20% go to the seaside and the rest are divided equally between camping and a city break.
A person is chosen at random. Given that the person chosen goes camping, find the probability that the person goes abroad.
When Joanna cooks, the probability that the meal is served on time is \(\frac{1}{5}\). The probability that the kitchen is left in a mess is \(\frac{3}{5}\). The probability that the meal is not served on time and the kitchen is not left in a mess is \(\frac{3}{10}\). Some of this information is shown in the following table.
| Kitchen left in a mess | Kitchen not left in a mess | Total | |
|---|---|---|---|
| Meal served on time | \(\frac{1}{5}\) | ||
| Meal not served on time | \(\frac{3}{10}\) | ||
| Total | 1 |
(i) Copy and complete the table.
(ii) Given that the kitchen is left in a mess, find the probability that the meal is not served on time.
Two fair 5-sided spinners, each with sides labelled 1, 2, 3, 4, 5, are spun at the same time. If the numbers obtained are equal, the score is 0. Otherwise, the score is the higher number minus the lower number.
Find the probability that the score is greater than 0 given that the score is not equal to 2.
Nikita goes shopping to buy a birthday present for her mother. She buys either a scarf, with probability 0.3, or a handbag. The probability that her mother will like the choice of scarf is 0.72. The probability that her mother will like the choice of handbag is x. This information is shown on the tree diagram. The probability that Nikita’s mother likes the present that Nikita buys is 0.783.
(i) Find x.
(ii) Given that Nikita’s mother does not like her present, find the probability that the present is a scarf.