HARD
AS and A Level
IMPORTANT
Earn 100

Two fair 4-sided dice, both with faces marked 1, 2, 3 and 4, are rolled.
Event A is 'the sum of the numbers obtained is a prime number'.
Event B is 'the product of the numbers obtained is an even number'

Determine, with justification, whether events A and B are independent.

Important Questions on Probability

MEDIUM
AS and A Level
IMPORTANT

Two fair 4-sided dice, both with faces marked 1, 2, 3 and 4, are rolled.
Event A is 'the sum of the numbers obtained is a prime number'.
Event B is 'the product of the numbers obtained is an even number'

Give a reason why events A and B are not mutually exclusive.

HARD
AS and A Level
IMPORTANT

Two ordinary fair dice are rolled.
Event X is 'the product of the two numbers obtained is odd'.
Event Y is 'the sum of the two numbers obtained is a multiple of 3 '.

Determine, giving reasons for your answer, whether X and Y are independent.

HARD
AS and A Level
IMPORTANT

Two ordinary fair dice are rolled.
Event X is 'the product of the two numbers obtained is odd'.
Event Y is 'the sum of the two numbers obtained is a multiple of 3 '.

Are events X and Y mutually exclusive? Justify your answer.

HARD
AS and A Level
IMPORTANT
A fair 8 -sided die has faces marked 1, 2, 3, 4, 5, 6, 7 and 8 . The score when the die is rolled is the number on the face that the die lands on. The die is rolled twice.
Event V is 'one of the scores is exactly 4 less than the other score'.
Event W is 'the product of the scores is less than 13 '.
Determine whether events V and W are independent, justifying your answer.
EASY
AS and A Level
IMPORTANT

Two hundred children are categorised by gender and by whether or not they own a bicycle. Of the 108 males, 60 own a bicycle, and altogether 90 children do not own a bicycle.

Tabulate these data.

HARD
AS and A Level
IMPORTANT

Two hundred children are categorised by gender and by whether or not they own a bicycle. Of the 108 males, 60 own a bicycle, and altogether 90 children do not own a bicycle.

Determine, giving reasons for your answer, whether ownership of a bicycle is independent of gender for these 200 children.

HARD
AS and A Level
IMPORTANT

Two hundred children are categorised by gender and by whether or not they own a bicycle. Of the 108 males, 60 own a bicycle, and altogether 90 children do not own a bicycle.

What percentage of the females and what percentage of the males own bicycles?

HARD
AS and A Level
IMPORTANT

At an election, it was found that people voted for Party X independently of their income group. The following table shows that 12400 people from three income groups voted altogether, and that 7440 of them voted for Party X.

  Low Medium High Totals
Party X a b c 7440
Totals 3100 6820 2480 12400

Find the value of a, of b and of c.