Multiple choice

Two balls are selected from two black and two red balls. The probability that the two balls will have no black balls is

  1. $\dfrac{1}{7}$
  2. $\dfrac{1}{5}$
  3. $\dfrac{1}{4}$
  4. $\dfrac{1}{6}$
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D Correct answer
Explanation

Total balls = 4. Choosing 2 balls = 4C2 = 6. We want no black balls, meaning both are red. There are 2 red balls, so 2C2 = 1 way. Probability = 1/6.

AI explanation

The total number of ways to select 2 balls from the 4 available is calculated using combinations, 4C2, which equals 6. Selecting no black balls means both selected balls must be red, and the number of ways to choose 2 red balls from the 2 available is 2C2, which equals 1. The probability is the ratio of favorable outcomes to total outcomes, which is 1/6.

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