Higher June 2023 Paper 2 Q13
13 Narin has two fair 6-sided dice.
Dice A has 2 red faces and 4 yellow faces.
Dice B has 1 red face and 5 yellow faces.
Narin is going to throw each dice once.
(a) Complete the probability tree diagram. (2)
(b) Work out the probability that both dice land on yellow. (2)
| Scheme | Marks |
|---|---|
\(\dfrac{4}{6}\) \(\dfrac{1}{6}, \dfrac{5}{6}, \dfrac{1}{6}, \dfrac{5}{6}\) | B2oe |
| (2) |
Notes
B2oe: B1 for \(\dfrac{4}{6}\) (or \(\dfrac{2}{3}\)) on LH bottom branch
B1 for all other branches correct
(allow 0.66 or 0.67 or better, 0.16 or 0.17 or better, 0.83 or better)
| Scheme | Marks |
|---|---|
| \(\text{``}{\dfrac{4}{6}}\text{''} \times \text{``}{\dfrac{5}{6}}\text{''}\) | M1ft |
Correct answer scores full marks (unless from obvious incorrect working) Answer: \(\dfrac{5}{9}\) | A1 |
| (2) | |
| (4 marks) |
Notes
M1ft: ft their tree diagram if probabilities less than 1
(only considering this product or 1 – (RR + RY + YR))
A1: oe eg \(\dfrac{20}{36}\) or (0.55(55…) or 55% or better or 56%