SOLUTION: A jar contains 10 red, 7 blue and 5 yellow marbles. Blue marbles are then added in order to change the probability of randomly selecting a blue marble from the jar to “greater than

Algebra ->  Probability-and-statistics -> SOLUTION: A jar contains 10 red, 7 blue and 5 yellow marbles. Blue marbles are then added in order to change the probability of randomly selecting a blue marble from the jar to “greater than      Log On


   



Question 336570: A jar contains 10 red, 7 blue and 5 yellow marbles. Blue marbles are then added in order to change the probability of randomly selecting a blue marble from the jar to “greater than 1/2”.What is the least number of blue marbles that must be added?
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
The probability before adding any blue balls is 10/(10+7+5)=10/22
Let x be the least number of blue marbles that must be added.
(10+x)/(22+x) > 1/2
10+x>(22+x)/2
20+2x>22+x
x>2
Since x is greater than 2 then x must be 3.
.
Ed