Multiple choice

There are $3$ red, $3$ white and $3$ green balls in a bag. One ball is drawn at random from a bag: $P$ is the event that ball is red. $Q$ is the event that ball is not green. $R$ is the event that ball is red or white. $S$ is the sample space. Which of the following options is correct?

  1. $n(S) = 9, n(P) =3, n(Q) = 6, n(R) = 6$
  2. $n(S) = 4, n(P) =3, n(Q) = 6, n(R) = 6$
  3. $n(S) = 6, n(P) =3, n(Q) = 6, n(R) = 6$
  4. $n(S) = 7, n(P) =3, n(Q) = 6, n(R) = 6$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total balls = 9. S = {all balls}, n(S) = 9. P = {red}, n(P) = 3. Q = {not green} = {red, white}, n(Q) = 6. R = {red or white}, n(R) = 6. All match option A.

AI explanation

The sample space S contains all 9 balls, so n(S) equals 9. Event P is drawing a red ball, giving n(P) as 3. Event Q is drawing a ball that is not green, meaning it is either red or white, giving n(Q) as 6. Event R is drawing a red or white ball, which also gives n(R) as 6.

Keep practicing — related questions