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

Q: Problem: how many positive integers less than 300 can be formed using the numbers 1 , 2 , 3 and 5 for the digits ? 
Options: a ) 48 , b ) 52 , c ) 66 , d ) 68 , e ) 84

A: b
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Q: Problem: a store has 10 bottles of juice , including 5 bottles of apple juice . in the evening , 6 bottles of juice are sold one by one . what is the probability of selling 3 bottles of apple juice among the 6 bottles ? assume that every bottle has an equal chance of being bought . 
Options: a ) 4 / 9 , b ) 6 / 11 , c ) 8 / 15 , d ) 10 / 21 , e ) 12 / 25

A: d
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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 heads up exactly once in 3 consecutive flips ? 
Options: a ) 0.125 , b ) 0.25 , c ) 0.75 , d ) 0.375 , e ) 0.666

A:
d
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