Foundation November 2023 Paper 3 Q24
24 Two bags contain only green discs and yellow discs.
Bag A contains 1 green disc and 4 yellow discs.
Bag B contains 3 green discs and 7 yellow discs.
One disc is picked at random from each bag.
(a) Complete the tree diagram with the correct probabilities. [2 marks]
(b) Work out the probability that both discs are green. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{1}{5}\) (Green) and \(\dfrac{4}{5}\) (Yellow) for Bag A | B1 | oe fractions, decimals or percentages |
| \(\dfrac{3}{10}\) (Green) and \(\dfrac{7}{10}\) (Yellow) on both sections for Bag B | B1 | oe fractions, decimals or percentages |
| Answer | Mark | Comments |
|---|---|---|
| their \(\dfrac{1}{5} \times\) their \(\dfrac{3}{10}\) | M1 | oe fractions or decimals ft their tree diagram with \(0 \lt\) both probabilities for Green \(\lt 1\) |
| \(\dfrac{3}{50}\) or 0.06 or 6% | A1ft | oe ft their tree diagram with \(0 \lt\) both probabilities for Green \(\lt 1\) |
Additional guidance
| Ignore incorrect simplification or conversion after correct answer seen | |
| 3 out of 50 or 3 : 50 without working for M1 | M0A0 |