4MA0 Foundation January 2017 Paper 2 Q18
18 Here is a biased five-sided spinner.
When the spinner is spun, it can land on red, orange, yellow, green or blue.
The probabilities that it lands on red, orange and yellow are given in the table.
| Colour | red | orange | yellow | green | blue |
|---|---|---|---|---|---|
| Probability | 0.4 | 0.2 | 0.1 |
The probability that the spinner lands on green is the same as the probability that the spinner lands on blue.
Michael spins the spinner once.
(a) Work out the probability that the spinner lands on green. (3)
Jenny spins the spinner 200 times.
(b) Work out an estimate for the number of times the spinner lands on red. (2)
| Scheme | Marks |
|---|---|
| 1 − 0.4 − 0.2 − 0.1 or 0.3 | M1 |
| \(\dfrac{1 - 0.4 - 0.2 - 0.1}{2}\) or \(\dfrac{\text{"}0.3\text{"}}{2}\) | M1 |
| 0.15 | A1 |
| (3) |
Notes
M1: dep
| Scheme | Marks |
|---|---|
| 200×0.4 | M1 |
| 80 | A1 |
| (2) | |
| (5 marks) |
Notes
A1: Note:
Award M1A1 for 80 out of 200
Award M1A0 for 80/200