A pair of dice is thrown. Let E be the event that the sum is greater than or equal to 10 and F be the event”5 appears of the first-die”. Find P(E/F). If F is the event”5 appears on at least one die”, find P(E/F). (same as above question)
We know, when a pair of dice is thrown, total possible outcomes are = 36
E=No of outcomes for getting sum greater than or equal to 10
{(4,6),(5,5),(5,6),(6,4),(6,5),(6,6)} = 6
Therefore, P(E) =
Case 1:
F= No of outcomes for 5 appears on first die =
= {(5,1),(5,2),(5,3),(5,4),(5,5),(5,6)} =6
Hence P(B) =
(E F ) = outcomes of getting a sum greater than or equal to 10 and first die showing 5
= {(5,6),(5,5)= 2
Hence P(E F) =
Therefore, =
(answer)
Case 2:
F = 5 appears on atleast one die =
{(1,5),(2,5),(3,5),(4,5),( 5,1),(5,2),(5,3),(5,4),(5,5),(5,6),(6,5)} = 11
P(F) =
(E F ) = outcomes of getting a sum greater than or equal to 10 and at least die showing 5
= {(5,6),(5,5),(6,5)}= 3
Hence P(E F) =
Therefore, =
(answer)