Question

what is the probability of the sum of two die will be greater than 8, given that the first is 6

Answer 1

The first die is 6, so you only need to focus on the second die

Answer 2

Rolling a 1 through 6, which of these numbers will add to 6 and give us a result that is larger than 8?

Answer 3

Can u please solve the whole sum?

Answer 4

Does 1 work?

Answer 5

Yes

Answer 6

So if the first die is 6 and the second die is 1, it will work?

Answer 7

But the total should be greater than 8

Answer 8

So 1 doesn't work

Answer 9

Yes it doesnt

Answer 10

What about 2?

Answer 11

No it says greater than 8 so should be numbers after two

Answer 12

good

Answer 13

What is the probability of rolling a 3, 4, 5, or 6?

Answer 14

(1/6) X 4

Answer 15

simplify and reduce that

Answer 16

2/3

Answer 17

you got it

Answer 18

Thats the answer?

Answer 19

yes

Answer 20

Oh.. Thanks! One more doubt

Answer 21

A die is rigged so that the probabilities of obtaining the different faces are proportional to the number on the faces (eg: a five is five times more likely to be rolled than one) find: the probability of obtaining a 6.

Answer 22

what did you get

Answer 23

1

Answer 24

1 means 100% certainty

Answer 25

so are you always going to roll a 6?

Answer 26

I know its wrong but how do you do it?

Answer 27

try it again, your answer should be between 0 and 1

Answer 28

Cant understnd

Answer 29

do you have your book with you?

Answer 30

Yes

Answer 31

did you read the section on probability?

Answer 32

I did

Answer 33

then you would know that all probabilities are between 0 and 1

Answer 34

I know it but the question says that a five is five times more likely to be rolled than one

Answer 35

So if u go by that assumption then it should be 1/6 X 6

Answer 36

no, if 6 is six times more likely than 1, then 1 is still a possible outcome

Answer 37

So how do i do it

Answer 38

If 2 is twice as likely as 1, then

P(X = 1) = k

P(X = 2) = 2k

Answer 39

Extend this out and add up all the probabilities. They should add to 1

k+2k+3k+4k+5k+6k = 1

Answer 40

Ok.. Then

Answer 41

Oh so 1/7X 6

Answer 42

No 1/21X6

Answer 43

Is it like that?

Answer 44

simplify and reduce

Answer 45

2/7

Answer 46

that's correct

Answer 47

Thanks

Answer 48

yw