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A die is rolled twice. What is the probability of showing a 5 on the first roll or an odd number on the second roll?Round your answer to three decimal places.

A die is rolled twice. What is the probability of showing a 5 on the first roll or-example-1
User Mazaneicha
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1 Answer

15 votes
15 votes
Answer:
Pr(rolling\text{ a 5 on the 1st row or an odd number on the 2nd roll\rparen = 0.667}

Step-by-step explanation:

Given:

A die is rolled twice

To find:

the probability of showing 5 on the 1st row and an odd number on the 2nd roll

Possible outcone of a die = {1, 2, 3, 4, 5, 6}

The total number from a die = 6

Pr(rolling a 5) = number of times 5 occurs/total number

number o times 5 occurs = 1

Pr(rolling a 5) = 1/6

Pr(rolling an odd number) = number of odd numbers/total

Odd numbers = {1, 3, 5}

number of odd numbers = 3

Pr(rolling an odd number) = 3/6

the probability (5 on the 1st row or an odd number on the 2nd roll = Pr(rolling a 5) + Pr(rolling an odd number)


\begin{gathered} Pr(rolling\text{ a 5 or an odd number\rparen = }(1)/(6)\text{ + }(3)/(6) \\ \\ Pr(rolling\text{ a 5 or an odd number\rparen= }(4)/(6)\text{ = 2/3} \\ \\ Pr(rolling\text{ a 5 or an odd number\rparen= 0.667} \\ \end{gathered}

A die is rolled twice. What is the probability of showing a 5 on the first roll or-example-1
User Rashmi
by
3.1k points
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