Question

Probablity Question

Answer 1

A die is thrown three times. Events A and B are defined as below:
A : 4 on the third throw
B : 6 on the first and 5 on the second throw
Find the probability of A given that B has already occurred

Answer 2

Don't you think that the first, second, and the third throws are independent of each other?

Answer 3

If we got six on the first throw, and five on the second, how does that affect the probability of four occurring on the third throw?

Answer 4

1,2, and 3 are different

Answer 5

need to use conditional probablity , i dont know how they affect

Answer 6

They don't. The probability is 1/6.

Answer 7

1/6 for which ?

Answer 8

We're given that B has already occurred. But who cares about what has occurred? We just want to see what the probability of getting a 4 is on the third throw. That is 1/6.

Answer 9

but i need to solve this by conditional probablity

Answer 10

if 4 had occured in 1st or 2nd place then

Answer 11

will it would have been 1/4 as usual

Answer 12

OK, the probability is either 1/6 * 1/6 * 1/6 or just 1/6 depending on the use of "given that B has already occurred".

Answer 13

lol m getting confused

Answer 14

what PK said is correct but if you want to do it conditional probability then here it is
P(A/B) = P(A (intersection) B ) / P(B)
P(A (intersection) B ) is the event where all the 3 throws have some specified values
P(B) is the event where only 2 are specified
I hope you can calculate both values

Answer 15

It is 1/6 as A and B are independent. No matter B happened or not, the probability of A happening is the same. Past results of die throws does not affect the future results of die throws.

Basically it is what ParthKohli is saying.