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

[Q]: Problem: in a bag containing 3 balls , a white ball was placed and then 1 ball was taken out at random . what is the probability that the extracted ball would turn on to be white , if all possible hypothesis concerning the color of theballs that initiallyin the bag were equally possible ? 
Options: a ) 2 / 3 , b ) 5 / 8 , c ) 5 / 9 , d ) 3 / 7 , e ) 4 / 7
[A]: b


[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 7 managers , if there are 2 managers who refuse to attend the meeting together . 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 11 , e ) 15
[A]: d


[Q]: Problem: if a coin has an equal probability of landing heads up or tails up each time it is flipped , what is the probability that the coin will land tails up exactly once in 3 consecutive flips ? 
Options: a ) 0.125 , b ) 0.375 , c ) 0.325 , d ) 0.5 , e ) 0.666
[A]:
b