Question
Fri January 28, 2011 By: Renuka Sahu

the probability of selecting a green marble at random from a jar that contains only green,white and yellow marbles is 1/4.the probability of selecting a white marble at random from the same jar is 1/3.if this jar contains 10 yellow marbles . what is the total number of marbles in the jar ?

Expert Reply
Sat January 29, 2011
Dear student,
 
Let the number of Green marbles be G and the number of White marbles be W.
 
Therefore, the total number of marbles is G + W + 10.
 
Prob(randomly selecting green marble) = G/(G+W+10) = 0.25
=> 3G = W + 10      ----(1)
 
Prob(randomly selecting white marble) = W/(G+W+10) = 0.33
=> 2W = G + 10      ----(2)
 
Solving the system of equations (1) and (2), we get
G = 6.
W = 8.
 
Therefore, the total number of marbles = 6 + 8 + 10 = 24.
 
Regards Topperlearning.
 
 
 
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