yahtzee large straight

bobbixler

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What is the probability of a large straight in one turn (3 throws) at Yahtzee? Assume you are going for a large straight.
 
What is the probability of a large straight in one turn (3 throws) at Yahtzee? Assume you are going for a large straight.

First define large straight.

Next how many ways can we get large straight in Yahtzee?

Please share your work with us, indicating exactly where you are stuck - so that we may know where to begin to help you.
 
Yahtzee rules

In Yahtzee one turn consists of up to 3 rolls of the dice. You roll 1-5 dice at once (your choice) on each of the 3 rolls. A large straight consists of either rolling a 12345 or 23456 after your 1-3 rolls. Order of the dice is not important. What is the probability of doing this assuming that is your goal?
 
Hello, bobbixler!

This problem is more elaborate that I had anticipated.
I can give you a start on the procedure . . . Let \(\displaystyle LS\) = "Large Straight".


What is the probability of a Large Straight in one turn (3 throws) at Yahtzee?
Assume you are going for a Large Straight.

First, consider only this LS: "1-2-3-4-5".


We could get it in one roll: .\(\displaystyle P(\text{1 roll}) \,=\,\left(\frac{1}{6}\right)^5\)


We could get it in two rolls.
There are 4 cases to consider.

4 numbers are in the LS: .\(\displaystyle {5\choose4}(\frac{1}{6})^4(\frac{5}{6})\)
We want the 5th: .\(\displaystyle \left(\frac{1}{6}\right)\)
. . \(\displaystyle P(\text{LS with 4 numbers}) \:=\:{5\choose4}(\frac{1}{6})^5(\frac{5}{6})\)

3 numbers are in the LS: .\(\displaystyle {5\choose3}(\frac{1}{6})^3(\frac{5}{6})^2\)
We want the 4th and 5th: .\(\displaystyle (\frac{1}{6})^2\)
. . \(\displaystyle P(\text{LS with 3 numbers}) \:=\:{5\choose3}(\frac{1}{6})^5(\frac{5}{6})^2\)

2 numbers are in the LS: .\(\displaystyle {5\choose2}(\frac{1}{6})^2(\frac{5}{6})^3\)
We want the 3rd, 4th and 5th: .\(\displaystyle (\frac{1}{6})^3\)
. . \(\displaystyle P(\text{LS with 2 numbers}) \:=\:{5\choose2}(\frac{1}{6})^5(\frac{5}{6})^3 \)

1 number is in the LS: .\(\displaystyle {5\choose1}(\frac{1}{6})(\frac{5}{6})^4\)
We want the 2nd, 3rd, 4th and 5th: .\(\displaystyle (\frac{1}[6})^4\)
. . \(\displaystyle P(\text{LS with 1 number}) \:=\:{5\choose1}(\frac{1}{6})^5(\frac{5}{6})^4\)


At this point, my brain turned to tapioca . . .


What does it mean "One number is in the Large Straight"?

If we rolled 3-6-6-6-6, we'd keep the 3 and reroll the 6's.

But it we rolled 1-1-2-2-6, which die is the "one"?
Wouldn't we keep a 1 and a 2 and reroll the other 3 dice?


And is there another case? ."No numbers are in the LS."
. . A player can reject all five dice and reroll all of them.
But would he?

What is the probability of "No numbers are in the LS" ?
. . Since the player will reject the roll, the probability is \(\displaystyle 1.\)

But he wouldn't reroll if he got a LS on his first roll.
And if he got 1-2-3-4-6, I'm sure he'd reroll the 6 only.


I need a nap . . .
 
the answer

As no one has given an answer I went ahead and wrote the code to solve the problem. The answer is about .249.
 
program solution ???

As no one has given an answer I went ahead and wrote the code to solve the problem. The answer is about .249.

Hi, I'm woking on this problem...... may I ask how you implement a program to solve this?
Did you just simply randomly throw the dice? and count the number of large straight?

Thanks!!!!!!!!!!!
 
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