What is the probability that the first 2 customers both get a 50% discount? What is the probability that none of the 1st 3 customers gets more than a 30% discou

Question

A clothing store advertises that every customer that walks into the store can throw a dice onto a table that has squares labeled with discount amounts. The table is divided into ten regions. 5 regions award 10%, 2 regions award 20%, 2 regions award 30%, and 1 region awards 50%.

Answer 1

As the table is divided into 10 regions, 

 

P(10) = 5 / 10 =0.5  ( There are 5 regions for 10% on the table)

P(20) = 2 / 10 =0.2

P(30) = 2 / 10 =0.2

P(50) = 1 / 10 = 0.1

 

P(first 2 customers both get 50%) = P(50) * P(50) = 0.1*0.1=0.01 or 1 / 100

 

P(none get more than 30%) = 1 - P(one gets 50%) + P(2 get 50%) + P(all 3 get 50 %)

 

P(only one gets 50%) = P(50)*P(No 50)*P(No 50) = 0.1*0.9*0.9 = 0.081

P( only 2 get 50%) = P(50)*P(50)*P(10) + P(50)*P(50)*P(20) + P(50)*P(50)*P(30)  = 0.009

P(all 3 get 50 %) = P(50)*P(50)*P(50) = 0.001

 

P(none get more than 30%) = 1 - 0.081 - 0.009 - 0.001 = 0.909