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# S1 help? Watch

1. A fair die is rolled five times. Find:
The probability that only the first and last rolls give a six.

It's probably really simple but I have like 3 possible answers...
2. What's the probability of rolling a six on the first roll?

What is the probability of NOT rolling a six on the next three?

What is the probability of rolling a six on the fifth roll?

How do you combine these results?
3. Well, I know it's 1/6 x 5/6 x 5/6 x 5/6 x 1/6...but doesn't the fact that it has to be the first and last roll matter?
4. (Original post by Raeile)
Well, I know it's 1/6 x 5/6 x 5/6 x 5/6 x 1/6...but doesn't the fact that it has to be the first and last roll matter?

Explanation: The probability of rolling a six is 1/6, and the probability of not rolling a six is 5/6.

Roll 1: P(Rolling a six) = 1/6
Roll 2: P(Not rolling a six) = 5/6
etc.

Multiplying it all, like you did at the end, give the answer.
5. Well, I thought it might include nPr because I thought the order mattered...aha ;D

But thank you!

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