Exam-Style Problems

โฌ… Back to Subchapter
Browsing as Guest. Progress, bookmarks and attempts are disabled. Log in to track your work.
Nov 2016 p62 q2
2917

Noor has 3 T-shirts, 4 blouses and 5 jumpers. She chooses 3 items at random. The random variable X is the number of T-shirts chosen.

  1. Show that the probability that Noor chooses exactly one T-shirt is \(\frac{27}{55}\).
  2. Draw up the probability distribution table for X.
Log in to record attempts.
Nov 2016 p61 q2
2918

Two fair six-sided dice with faces numbered 1, 2, 3, 4, 5, 6 are thrown and the two scores are noted. The difference between the two scores is defined as follows.

  • If the scores are equal the difference is zero.
  • If the scores are not equal the difference is the larger score minus the smaller score.

Find the expectation of the difference between the two scores.

Log in to record attempts.
June 2016 p63 q3
2919

Two ordinary fair dice are thrown. The resulting score is found as follows.

  • If the two dice show different numbers, the score is the smaller of the two numbers.
  • If the two dice show equal numbers, the score is 0.

(i) Draw up the probability distribution table for the score.

(ii) Calculate the expected score.

Log in to record attempts.
Nov 2022 p53 q4
2920

Three fair 4-sided spinners each have sides labelled 1, 2, 3, 4. The spinners are spun at the same time and the number on the side on which each spinner lands is recorded. The random variable X denotes the highest number recorded.

(a) Show that \(P(X = 2) = \frac{7}{64}\).

(b) Complete the probability distribution table for \(X\).

x1234
\(P(X = x)\)\(\frac{7}{64}\)\(\frac{19}{64}\)
Log in to record attempts.
June 2016 p62 q3
2921

A particular type of bird lays 1, 2, 3 or 4 eggs in a nest each year. The probability of x eggs is equal to kx, where k is a constant.

  1. Draw up a probability distribution table, in terms of k, for the number of eggs laid in a year and find the value of k.
  2. Find the mean and variance of the number of eggs laid in a year by this type of bird.
Log in to record attempts.
โฌ… Back to Subchapter Load more