Exam-Style Problems

⬅ Back to Subchapter
Browsing as Guest. Progress, bookmarks and attempts are disabled. Log in to track your work.
Nov 2003 p6 q5
2647

In a certain country 54% of the population is male. It is known that 5% of the males are colour-blind and 2% of the females are colour-blind. A person is chosen at random and found to be colour-blind. By drawing a tree diagram, or otherwise, find the probability that this person is male.

Log in to record attempts.
June 2022 p53 q6
2648

Sajid is practising for a long jump competition. He counts any jump that is longer than 6 m as a success. On any day, the probability that he has a success with his first jump is 0.2. For any subsequent jump, the probability of a success is 0.3 if the previous jump was a success and 0.1 otherwise. Sajid makes three jumps.

(a) Draw a tree diagram to illustrate this information, showing all the probabilities.

(b) Find the probability that Sajid has exactly one success given that he has at least one success.

On another day, Sajid makes six jumps.

(c) Find the probability that only his first three jumps are successes or only his last three jumps are successes.

Log in to record attempts.
June 2003 p6 q6
2649

The people living in 3 houses are classified as children (C), parents (P) or grandparents (G). The numbers living in each house are shown in the table below.

House number 1House number 2House number 3
4C, 1P, 2G2C, 2P, 3G1C, 1G
  1. All the people in all 3 houses meet for a party. One person at the party is chosen at random. Calculate the probability of choosing a grandparent. [2]
  2. A house is chosen at random. Then a person in that house is chosen at random. Using a tree diagram, or otherwise, calculate the probability that the person chosen is a grandparent. [3]
  3. Given that the person chosen by the method in part (ii) is a grandparent, calculate the probability that there is also a parent living in the house. [4]
Log in to record attempts.
Nov 2002 p6 q5
2650

Rachel and Anna play each other at badminton. Each game results in either a win for Rachel or a win for Anna. The probability of Rachel winning the first game is 0.6. If Rachel wins a particular game, the probability of her winning the next game is 0.7, but if she loses, the probability of her winning the next game is 0.4. By using a tree diagram, or otherwise,

  1. find the conditional probability that Rachel wins the first game, given that she loses the second,
  2. find the probability that Rachel wins 2 games and loses 1 game out of the first three games they play.
Log in to record attempts.
June 2022 p52 q7
2651

Hanna buys 12 hollow chocolate eggs that each contain a sweet. The eggs look identical but Hanna knows that 3 contain a red sweet, 4 contain an orange sweet and 5 contain a yellow sweet. Each of Hanna’s three children in turn randomly chooses and eats one of the eggs, keeping the sweet it contained.

(a) Find the probability that all 3 eggs chosen contain the same colour sweet.

(b) Find the probability that all 3 eggs chosen contain a yellow sweet, given that all three children have the same colour sweet.

(c) Find the probability that at least one of Hanna’s three children chooses an egg that contains an orange sweet.

Log in to record attempts.
⬅ Back to Subchapter Load more