Higher June 2019 Paper 1 Q5
5 Becky has a biased 6-sided dice.
The table gives information about the probability that, when the dice is thrown, it will land on each number.
| Number | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| Probability | \(2x\) | 0.18 | \(2x\) | \(3x\) | 0.26 | \(x\) |
Becky is going to throw the dice 200 times.
Work out an estimate for the number of times that the dice will land on an even number.
(4)
| Scheme | Marks |
|---|---|
| \(2x + 0.18 + 2x + 3x + 0.26 + x = 1\) or 1 – (0.18 + 0.26) (= 0.56) | M1 |
| \(x\) = (1 – 0.18 – 0.26) ÷ (2 + 2 + 3 + 1) (= 0.07) | M1 |
| eg (0.18 + 4 × “0.07”) × 200 or 0.46 × 200 or 36 + 42 + 14 oe | M1 |
| 92 | A1 |
| (4) | |
| (4 marks) |
Notes
M1: dep on M2 and probabilities between 0 and 1
or \(\dfrac{92}{200}\), oe with 92 seen