Today Puzzle #785

Puzzle No. 785– Friday 17 July 2020
If wearing a face covering indoors reduces the risk of transmission by 80%, and thorough implementation of all other mitigation measures independently reduces risk by a further 90%, how much have you reduced the risk by using them all?
Today’s #PuzzleForToday has been set by Dr Shaun Fitzgerald, Fellow of Girton College
Click here for the answer
Risk = (1-80%) x (1-90%) = 2% so you have reduced the risk by 98%.

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