Question

What is the probability of either event occurring when you roll adie?Event A: Rolling a prime numberEvent B: Rolling a 4Express your answer as a simplified fraction.

Answer 1

Assuming it is a normal 6-sided die.

We have 6 possible possibilities : 1,2,3,4,5,6.
In these 6 numbers, only 2,3 and 5 are prime numbers.

Therefore, the probability of event A = 3/6 = 1/2.

There is only one 4 in this sample -> The probability of event B = 1/6.

Answer 2

Given:

Roll a die.

Required:

We need to find the probability of rolling a prime number and a number 4.

Step-by-step explanation:

A)

A die has sic sides and is numbered from 1 to 6.

The sample space, S ={1,2,3,4,5,6}

Let A be the event of rolling a prime number.

Recall that a prime number is a whole number greater than 1 whose only factors are 1 and itself.

`A=\lbrace2,3,5\rbrace`
`n(A)=3`

The probability of rolling a prime number is P(A).

`P(A)=(n(A))/(n(S))`
`P(A)=(3)/(6)`
`P(A)=(1)/(2)`

B)

Let B be the event of rolling a number 4.

`B=\lbrace4\rbrace`
`n(B)=1`

The probability of rolling a number 4 is P(B).

`P(B)=(n(B))/(n(S))`
`P(B)=(1)/(6)`

Final answer:

The probability of rolling a prime number is 1/2.

The probability of rolling a 4 is 1/6.