Edexcel S1 2016 June — Question 4

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2016
SessionJune
TopicIndependent Events
TypeVenn diagram with independence constraint

4. The Venn diagram shows the probabilities of customer bookings at Harry’s hotel.
\(R\) is the event that a customer books a room
\(B\) is the event that a customer books breakfast
\(D\) is the event that a customer books dinner
\(u\) and \(t\) are probabilities.
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  1. Write down the probability that a customer books breakfast but does not book a room. Given that the events \(B\) and \(D\) are independent
  2. find the value of \(t\)
  3. hence find the value of \(u\)
  4. Find
    1. \(\quad\) P( \(D \mid R \cap B\) )
    2. \(\mathrm { P } \left( D \mid R \cap B ^ { \prime } \right)\) A coach load of 77 customers arrive at Harry’s hotel. Of these 77 customers 40 have booked a room and breakfast 37 have booked a room without breakfast
  5. Estimate how many of these 77 customers will book dinner.