Multiple choice

A bag contain $4$ white and $2$ black balls. Two balls are drawn at random. The probability that they are of the same colour is ________.

  1. $\dfrac{5}{7}$
  2. $\dfrac{1}{7}$
  3. $\dfrac{7}{15}$
  4. $\dfrac{1}{15}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total balls = 6. Ways to choose 2 balls = 6C2 = 15. Ways to choose 2 white = 4C2 = 6. Ways to choose 2 black = 2C2 = 1. Total favorable = 6 + 1 = 7. Probability = 7/15.

AI explanation

The total number of ways to draw 2 balls from 6 is found using the combinations formula 6C2, which equals 15. The favorable outcomes of drawing balls of the same color consist of drawing 2 white balls from 4 (4C2 = 6) or drawing 2 black balls from 2 (2C2 = 1), adding up to 7 favorable outcomes. The probability is 7 divided by 15. The probability that they are of the same colour is 7/15.

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