passwella.
Menu

WAEC Mathematics 1996 Question 49

Question 49

Probability

A bag contains 3 red, 4 black and 5 green identical balls. Two balls are picked at random, one after the other without replacement. Find the probability that one is red and the other is green

  1. A.2/3
  2. B.5/11
  3. C.5/22
  4. D.5/24
  5. E.5/48.
Show the answer and explanation

Answer: C (5/22)

Explanation

There are 12 balls. P(red then green) = 3/12 × 5/11 = 15/132, and P(green then red) = 5/12 × 3/11 = 15/132. Total = 30/132 = 5/22.