Stage: 4 Challenge Level: 
Two bags contain different numbers of red and blue balls. A ball is removed from one of the bags (it is not known from which bag). The ball is blue. What is the probability that it was removed from bag A?
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Bag A 2 RED 3 BLUE |
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Bag B 3 RED 4 BLUE |
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Tree diagrams. Experimental probability. Forces. Rigid Bodies. Conditional probability. physics. Short problems. Combining probabilities. engineering. Theoretical probability.
Published May 1997.
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