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

Q: Problem: a box contains 4 red balls and 4 black balls . one by one , every ball is selected at random without replacement . what is the probability that the fourth ball selected is black ? 
Options: a ) 1 / 4 , b ) 1 / 2 , c ) 1 / 2 , d ) 5 / 8 , e ) 2

A: e
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Q: Problem: how many different ways can 2 students be seated in a row of 4 desks , so that there is always at least one empty desk between the students ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 6 , e ) 12

A: d
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Q: Problem: a bag contains 2 white marbles and 2 black marbles . if each of 2 girls and 2 boys randomly selects and keeps a marble , what is the probability that all of the girls select the same colored marble ? 
Options: a ) 1 / 35 , b ) 1 / 10 , c ) 1 / 3 , d ) 1 / 4 , e ) 1 / 5

A:
c
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