Higher November 2024 Paper 1 Q13
13 The probability that Thomas gets to work early on Saturday is 0.7
If Thomas gets to work early on Saturday, the probability that he will get to work early on Sunday is 0.9
If Thomas does not get to work early on Saturday, the probability that he will get to work early on Sunday is 0.6
(a) Use this information to complete the probability tree diagram. (2)
(b) Work out the probability that Thomas gets to work early on both Saturday and Sunday. (2)
| Scheme | Marks |
|---|---|
 Answer: Correct probabilities | B2 |
| (2) |
Notes
B2: for all 3 correct pairs of probabilities on the correct branches
If not B2 then award B1 for one correct pair of probabilities on a correct branch
Allow equivalent fractions
0.7 and 0.3 counts as a pair
| Scheme | Marks |
|---|---|
| 0.7 × “0.9” oe | M1ft |
| Correct answer scores full marks (unless from obvious incorrect working) Answer: 0.63 | A1 |
| (2) | |
| (4 marks) |
Notes
M1ft: (probabilities < 1) for a complete method involving one product
A1: ft oe eg \(\dfrac{63}{100}\) or 63%