80 office workers were surveyed about which productivity apps they use: Slack, Zoom, and Trello. Every worker used at least one of these applications. 10 of the workers use all three applications. 35 of the workers use Trello. 45 of the workers use Slack. 22 of the workers use Slack and Zoom. 8 of the workers use Slack and Trello but not Zoom. 5 of the workers use Zoom and Trello but not Slack.
Two of the 80 workers are chosen at random. Work out the probability that they both use Zoom.
Practise OCR GCSE Maths Conditional Probability with exam-style questions for Foundation and Higher tier. 28 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.