An urn contains g green marbles and b blue marbles. If 2 green marbles and 5 blue marbles are added, and then one marble is selected at random from the urn, what is the probability that a blue marble will be drawn?  Choose the correct answer:
A) b/(b+g)  B) (b+5)/(g+3)  C) (b+5)/(b+g+7)  D) (b+5)/(b+g+3)  E) b/(b+g+5)
no of fav outcomes i.e. blue MArbles = b+5   Total no of outcomes i.e. total Marbles = (b+5)+(g+2)= b+g+7   probability = (b+5) /(b+g+7)   Answer (b+5)/(b+g+7)
<result>C</result>
An urn contains g green marbles and b blue marbles. If 2 green marbles and 5 blue marbles are added, and then one marble is selected at random from the urn, what is the probability that a blue marble will be drawn?