FoundationMultiple choice
Which bag was it? · Part 1 of 3
Bag A holds 8 blue and 4 red balls; bag B holds 4 blue and 8 red. A fair coin picks one bag, and you draw from it without seeing which.
You draw one ball and it is blue. What is the probability you are drawing from bag B?
- A1/3
- B1/2, since the coin was fair
- C2/3, the share of blue balls in bag A
- D1/6, the prior 1/2 times the 1/3 chance of blue from B
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