2023 SAJC P2 Q6

2023 SAJC P2 Q6

8 marks
Prelims

A bag contains \(5\) red balls and \(3\) blue balls. In a game, Anne removes balls at random from the bag, one at a time, without replacement, until she has taken out \(2\) red balls. The total number of balls Anne removes from the bag is denoted by \(X\).

  1. Find \(\mathrm{P}\left( X=x \right)\) for all possible values of \(x\).[3]
  2. Find \(\mathrm{E}\left( X \right)\) and \(\mathrm{Var}\left( X \right)\).[3]

Anne pays \(\$1\) every time she removes a ball and she will receive \(\$y\) once she gets \(2\) red balls.

  1. Calculate the value of \(y\) if the game is fair.[2]

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs tuition enrolment.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:(i) \({\frac{1}{14}}\) (ii) \({\frac{6}{7}}\) (iii) \({3}\)

Need help? Join our JC Math tuition classes.

Learn more