In this task, you need to provide the correct option for a given problem on probability from the provided options.

[Q]: Problem: three unbiased coins are tossed . what is the probability of getting 1 heads , 1 tail ? 
Options: a ) 3 / 4 , b ) 1 / 4 , c ) 3 / 8 , d ) 7 / 8 , e ) 2 / 8
[A]: e


[Q]: Problem: x , y , and z are all unique numbers . if x is chosen randomly from the set { 10 , 11 } and y and z are chosen randomly from the set { 20 , 21 , 22 , 23 } , what is the probability that x and y are prime and z is not ? 
Options: a ) 1 / 5 , b ) 3 / 20 , c ) 1 / 8 , d ) 3 / 10 , e ) 1 / 10
[A]: c


[Q]: Problem: a meeting has to be conducted with 5 managers . find the number of ways in which the managers may be selected from among 9 managers , if 3 managers will not attend the meeting together . 
Options: a ) 1.24 , b ) 2.91 , c ) 3.12 , d ) 4.126 , e ) 5.15
[A]:
a