EASY
AS and A Level
IMPORTANT
Earn 100

There is a 43% chance that Riya meets her friend Jasmine when she travels to work. Given that Riya walks to work and does not meet Jasmine 30% of the time, and that she travels to work by a different method and meets Jasmine 25% of the time, find the probability that Riya walks to work on any particular day.

50% studentsanswered this correctly

Important Questions on Probability

EASY
AS and A Level
IMPORTANT
Aaliyah buys a randomly selected magazine that contains a crossword puzzle on five randomly chosen days of each week. On 84% of the occasions that she buys a magazine, she attempts its crossword, which she manages to complete 60% of the time. Find the probability that, on any particular day, Aaliyah does not complete the crossword in a magazine.
EASY
AS and A Level
IMPORTANT

Four quality-control officers were asked to test 1214 randomly selected electronic components from a company's production line, and to report the proportions that they found to be defective. The proportions reported were:
2333, 3411, 0187 and 4283.

These figures confirm what the manager thought; that about k% of the components produced are defective. Of the 7150 components that will be produced next month, approximately how many does the manager expect to be defective?

EASY
AS and A Level
IMPORTANT
Three referees are needed at an international tournament and there are 12 to choose from: three from Bosnia, four from Chad and five from Denmark. If the referees are selected at random, find the probability that at least two of them are from the same country.
EASY
AS and A Level
IMPORTANT

The diagram opposite gives details about a company's 115 employees. For example, it employs four unqualified, part-time females.

Two employees are selected at random. Find the probability that:

Question Image

one is a qualified male and the other is an unqualified female

EASY
AS and A Level
IMPORTANT

The diagram opposite gives details about a company's 115 employees. For example, it employs four unqualified, part-time females.

Two employees are selected at random. Find the probability that:

Question Image

both are unqualified, given that neither is employed part-time.

EASY
AS and A Level
IMPORTANT

The numbers of books read in the past 3 months by the members of a reading club are shown in the following table.

No. books <2 2-4 5-7 8-9 10 >10
No. members f 3 5 22 7 2 1

Find the probability that three randomly selected members have all read fewer than eight books, given that they have all read more than four books.

EASY
AS and A Level
IMPORTANT
When they are switched on, certain small devices independently produce outputs of 1, 2 or 3 volts with respective probabilities of 0.3, 0.6 and 0.1. Find the probability that three of these devices produce an output with a sum of 5 or 6 volts.
EASY
AS and A Level
IMPORTANT

One hundred people are attending a conference. The following Venn diagram shows how many are male M, have brown eyes (BE) and are right-handed (RH).

Question Image

Given that there are 43 males with brown eyes, 42 right-handed males and 46 right-handed people with brown eyes, copy and complete the Venn diagram.