Intermediate November 2023 Unit 1 Q16
16. Beti walks her dog to a local park and back home every day.
She can either walk along a footpath or along a pavement at the side of a road.
The probability that Beti walks to the park along the footpath is \(\dfrac{3}{5}\).
The probability that Beti walks home from the park along the road is \(\dfrac{2}{7}\).
Her decisions on which routes to walk to and from the park are independent of each other.
(a) Complete the tree diagram below. [2]
(b) Find the probability that Beti walks to and from the park along the footpath. [2]
| Scheme | Marks | Comments |
|---|---|---|
Complete diagram | B2 | If B2 not awarded, award B1 for one of the following:
|
| Scheme | Marks | Comments |
|---|---|---|
| \(\dfrac{3}{5} \times \dfrac{5}{7}\) or equivalent | M1 | FT \(\frac{3}{5}\) × ‘their \(\frac{5}{7}\)’ (on ‘uppermost footpath home branch’) provided less than 1. |
| \(\dfrac{15}{35}\) or equivalent ISW | A1 |