EASY
AS and A Level
IMPORTANT
Earn 100

A fair triangular spinner has sides labelled 0,1 and 2, and another fair triangular spinner has sides labelled -1,0 and 1. The score, X, is equal to the sum of the squares of the two numbers on which the spinners come to rest.

List the five possible values of X.

Important Questions on Probability Distributions

EASY
AS and A Level
IMPORTANT

A fair triangular spinner has sides labelled 0,1 and 2, and another fair triangular spinner has sides labelled -1,0 and 1. The score, X, is equal to the sum of the squares of the two numbers on which the spinners come to rest.

Draw up the probability distribution table for X.

EASY
AS and A Level
IMPORTANT

A fair triangular spinner has sides labelled 0,1 and 2, and another fair triangular spinner has sides labelled -1,0 and 1. The score, X, is equal to the sum of the squares of the two numbers on which the spinners come to rest.

Given that X<4, find the probability that a score of 1 is obtained with at least one of the spinners.

EASY
AS and A Level
IMPORTANT

A fair triangular spinner has sides labelled 0,1 and 2, and another fair triangular spinner has sides labelled -1,0 and 1. The score, X, is equal to the sum of the squares of the two numbers on which the spinners come to rest.

Find the exact value of a, such that the standard deviation of X is 1a×EX.

EASY
AS and A Level
IMPORTANT

A discrete random variable X,  where X2, 3, 4, 5, is such that PX=x=b-x230. Calculate the two possible values of b.

EASY
AS and A Level
IMPORTANT

A discrete random variable X,  where X2, 3, 4, 5, is such that PX=x=b-x230. Hence, find P(2<X<5).

EASY
AS and A Level
IMPORTANT

Set A consists of the ten digits 0, 0, 0, 0, 0, 0, 2, 2, 2, 4
Set B consists of the seven digits 0, 0, 0, 0, 2, 2, 2
One digit is chosen at random from each set. The random variable X is defined as the sum of these two digits.

Show that P(X=2)=37.

EASY
AS and A Level
IMPORTANT

Set A consists of the ten digits 0, 0, 0, 0, 0, 0, 2, 2, 2, 4
Set B consists of the seven digits 0, 0, 0, 0, 2, 2, 2
One digit is chosen at random from each set. The random variable X is defined as the sum of these two digits.

Tabulate the probability distribution of X.

EASY
AS and A Level
IMPORTANT

Set A consists of the ten digits 0, 0, 0, 0, 0, 0, 2, 2, 2, 4
Set B consists of the seven digits 0, 0, 0, 0, 2, 2, 2
One digit is chosen at random from each set. The random variable X is defined as the sum of these two digits.

Find EX and Var X.