24.a die is thrown twice. What is probability that
(1) 5 will not come up either time? (ü) 5 will come up at least once?
Answers
ANSWER
Throwing a die twice and throwing two dice simultaneously are treated as the same experiment.
Sample space ={(1,1),(1,2),(1,3),(1,4),(1,5),(1,6)
(2,1),(2,2),(2,3),(2,4),(2,5),(2,6)
(3,1),(3,2),(3,3),(3,4),(3,5),(3,6)
(4,1),(4,2),(4,3),(4,4),(4,5),(4,6)
(5,1),(5,2),(5,3),(5,4),(5,5),(5,6)
(6,1),(6,2),(6,3),(6,4),(6,5),(6,6)}
i) P(5 will not come up either time)= Number of times 5 does not show divided by total number of outcomes
P(5 will not come up either time)=
25 by 36
ii) P(5 will come up at least once)= Number of times 5 shows up at least once divided by total number of outcomes
P(5 will come up at least once)=
11 by 36