A bag has 7 red balls and 4 white balls. Two balls are drawn one after another without replacement. Find the probability that both are red.
Answer and explanation
Correct answer: B.
- Step 1: ; then .
- Step 2: Multiply: .
Answer
.
Why not the others: : it treats the draws as replaced. : it counts one red and one white. : it adds instead of multiplying.
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