4400 Higher November 2004 Paper 4 Q4
4 Here is a 4-sided spinner.

The sides of the spinner are labelled 1, 2, 3 and 4.
The spinner is biased.
The probability that the spinner will land on each of the numbers 1, 2 and 3 is given in the table.
| Number | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| Probability | 0.2 | 0.1 | 0.4 |
(a) Work out the probability that the spinner will land on 4 (2)
Tom spun the spinner a number of times.
The number of times it landed on 1 was 85
(b) Work out an estimate for the number of times the spinner landed on 3 (1)
| Scheme | Marks |
|---|---|
| 1 − (0.2 + 0.1 + 0.4) | M1 |
| 0.3 | A1 |
| (2) |
| Scheme | Marks |
|---|---|
| 170 | B1 |
| (1) | |
| (3 marks) |
Notes
B1: cao