A bag contains 4 red and 6 blue counters. Two counters are taken at random without replacement. What is the probability that they are the same colour?
Answer and explanation
Correct answer: D.
- Step 1: Both red: .
- Step 2: Both blue: .
- Step 3: Add: .
Answer
.
Why not the others: is the answer if the counter is replaced, is the chance of the first being red and is the chance of different colours.
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