EASY
AS and A Level
IMPORTANT
Earn 100

Every Friday evening Sunil either cooks a meal for Mina or buys her a take-away meal. The probability that he buys a takeaway meal is 0.24. If Sunil cooks the meal, the probability that Mina enjoys it is 0.75, and if he buys her a takeaway meal, the probability that she does not enjoy it is x. This information is shown in the following tree diagram.

The probability that Sunil buys a take-away meal and Mina enjoys it is 0.156.

Question Image

Find the value of x.

Important Questions on Practice Exam-Style Paper

HARD
AS and A Level
IMPORTANT

Every Friday evening Sunil either cooks a meal for Mina or buys her a take-away meal. The probability that he buys a takeaway meal is 0.24. If Sunil cooks the meal, the probability that Mina enjoys it is 0.75, and if he buys her a takeaway meal, the probability that she does not enjoy it is x. This information is shown in the following tree diagram.

The probability that Sunil buys a take-away meal and Mina enjoys it is 0.156.

Question Image

Given that Mina does not enjoy her Friday meal, find the probability that Sunil cooked it. (Round off to three decimal places)

EASY
AS and A Level
IMPORTANT

The following histogram summarises the total distance covered on each of 123 taxi journeys provided for customers of Jollicabs during the weekend.

Question Image

Find the upper boundary of the range of distances covered on these journeys.

EASY
AS and A Level
IMPORTANT

The following histogram summarises the total distance covered on each of 123 the taxi journeys provided for customers of Jollicabs during the weekend.

Question Image

Estimate the number of journeys that covered a total distance from 8 to 13 kilometres.

MEDIUM
AS and A Level
IMPORTANT

The following histogram summarises the total distance covered on each of 123 taxi journeys provided for customers of Jollicabs during the weekend.

Question Image

Calculate an estimate of the mean distance covered on these 123 journeys.

MEDIUM
AS and A Level
IMPORTANT

In each of a series of independent trials, a success occurs with a constant probability of 0.9.

The probability that none of the first n trials results in a failure is less than 0.3. Find the least possible value of n.

EASY
AS and A Level
IMPORTANT

In each of a series of independent trials, a success occurs with a constant probability of 0.9.

State the most likely trial in which the first success will occur.

MEDIUM
AS and A Level
IMPORTANT

In each of a series of independent trials, a success occurs with a constant probability of 0.9.

Use a suitable approximation to calculate an estimate of the probability that fewer than 70 successes occur in 80 trials.

EASY
AS and A Level
IMPORTANT

The following stem-and-leaf diagram shows the number of shots taken by 10 players to complete a round of golf.

61y Key617012x represents 8019961 shots 

Given that the median number of shots is 74.5 and that the mean number of shots is 75.4, find the value of x and of y.

The numbers of golf shots are summarised in a box-and-whisker diagram, as shown.

Question Image