Foundation June 2022 Paper 2 Q20
20 Lorena gets a train at the same time each morning to go to work.
She gets a train at the same time each evening to come home.
The probability tree diagram shows the probabilities of each train arriving late.
(a) Complete the probability tree diagram.
(2)

For a day that Lorena goes to work,
(b) work out the probability that the train to work and the train home will both arrive late. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| 0.87, 0.94, 0.94 | B2 | for all probabilities correct |
| (B1 | for 0.87 or 0.94 correctly placed) |
Additional guidance
Accept any equivalent fraction, eg \(\dfrac{87}{100}, \dfrac{47}{50}\)
or equivalent percentage form 87%, 94%
| Answer | Mark | Mark scheme |
|---|---|---|
| 0.0078 | M1 | for \(0.13 \times 0.06\) oe |
| A1 | 0.0078 oe |
Additional guidance
Accept any equivalent fraction, eg \(\dfrac{39}{5000}\)
or equivalent percentage form 0.78%
or \(7.8 \times 10^{-3}\)