Foundation June 2017 Paper 1 Q19

OCRFoundationCurrent spec4 marksTree Diagrams

19 Kirsty either travels by bus or walks when she visits the shops.
The probability that she catches the bus to the shops is 0.3.
The probability that she catches the bus from the shops is 0.8.

Tree diagram. To the shops: Bus 0.3, Walks blank. From the shops, after each branch: Bus blank, Walks blank
(a) Complete the tree diagram. [2]
(b) Show that the probability that Kirsty walks at least one way is 0.76. [2]