148k views
5 votes
The question is in the picture

The question is in the picture-example-1
User Jay Wang
by
9.2k points

1 Answer

4 votes

Given


S=\mleft\lbrace1,2,3,4,5,6,7,8,9\mright\rbrace

by selecting two numbers from S, the number of possible outcomes is


n(S)=9*9=81

Let E be the event that selecting two numbers randomly and their sum is 12 with replacement.


E=\lbrack(3,9),(4,8),(5,7),(6,6),(7,5),(8,4),(9,3)\}
n(E)=7

The probability is


P(E)=(n(E))/(n(S))

Substitute values, we get

h is


P(E)=(7)/(81)

b)without replacement

Areplacementout


A=\mleft\lbrace(3,9\mright),(4,8),(5,7),(7,5),(8,4),(9,3)\}
n(A)=6


P(A)=(n(A))/(n(S))

Substitute the values, we get


P(A)=(6)/(81)=(2)/(27)

The probability that the sum is 12 if selecting two numbers without replacement


P(A)=(2)/(27)

User Robert Casey
by
7.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories