4MA0 Higher June 2013 Paper 4 Q15
15 Peter and John play two games of badminton against each other.
For each game, the probability that Peter wins is 0.15
(a) Complete the probability tree diagram.
(3)

(b) Calculate the probability that Peter wins both games. (2)
| Scheme | Marks |
|---|---|
| 0.85 on lower branch | B1 |
| Binary tree structure | B1 |
| All labels & values correct | B1 |
| (3) |
Notes
B1: on lower branch for first game
B1: 0.15 & 0.85 in correct position + labels
| Scheme | Marks |
|---|---|
| 0.15 x 0.15 | M1 |
| 0.0225 oe | A1 |
| (2) |
Notes
A1: 9/400 etc