Question 452509
th problem asks a shop owner has a bag containing 15 red marbles and 1 orange marble if the owner wants to make sure the probability of choosing an orange marble is 2/5 how many orange marbles does she need to add?
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Let the # she needs to add be "x":
Solve:
(1+x)/(16+x) = 2/5
5+5x = 32+2x
3x = 27
x = 9 (# of orange marbles she needs to add)
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Cheers,
Stan H.