Maths Gcse Past Papers Edexcel Higher
GCSE Edexcel Maths Higher Calc Probability Question?
I’m revising for the exam tomorrow, and i remember there was a probability question from a past paper I had no idea to do, so here’s an example to see if you can help
Let’s say a man travels to work with a choice of two methods of transport, and these are the probabilities of him picking the certain mode of transport and the other probabilities are whether that mode of transport will make him late.
Bus 4/5 —————- Late 3/7 Early 4/7
Car 1/5 —————– Late 2/7 Early 5/7
Then the question said, the man was late work out the probability he caught the bus.
Any suggestions?
Thanks
P[bus & late] = 4/5 * 3/7 = 12/35
P[car & late] = 1/5 * 2/7 = 2/35
P[late] = sum of the above = 14/35
P[bus | late] = P[bus & late] / P[late]
= [12/35] / [14/35]
= 12/14
= 6/7
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Edexcel C3 June 2007 Question 6 b,c