Rolling dice to win

Hi, I have a question about my winning percent in the following game.

I have two dices and have to roll 7 to win and its my turn to roll. If i get a double (2,2)(3,3 etc) i get to roll again for as many times as i get a double. Can you help me estimate my chance of winning on my next move to the nearest percent or at least tell me how to think?

thanks in advance.

20%

We normally don't do homework here but this was too easy.

To figure it out, simply write down and every combination possible with two dice, and add them up. Then come up with the percentage.

Quote: Madski

Hi, I have a question about my winning percent in the following game.

I have two dices and have to roll 7 to win and its my turn to roll. If i get a double (2,2)(3,3 etc) i get to roll again for as many times as i get a double. Can you help me estimate my chance of winning on my next move to the nearest percent or at least tell me how to think?

thanks in advance.

Probability of rolling a double = 1/6
Probability of rolling a seven = 1/6

You “win” if you roll a seven on the first roll. Again, that has probability of 1/6.
OR you roll a double on the first roll and then a seven on the next. Probability of that is: (1/6)(1/6)
OR you roll two doubles and then a seven. Probability of that is (1/6)(1/6)(1/6)
...and so on.

Total probability of winning is the sum of all this. Hopefully the pattern is clear.
P(win) = 1/6 + (1/6)² + (1/6)³ + … = 1/5

You did the hard way. Doubles are ignored.

Six ways to win and 24 ways to lose. So the answer is 6 out of 30. 6/30 = 20%.

Quote: DJTeddyBear

You did the hard way. Doubles are ignored.

Six ways to win and 24 ways to lose. So the answer is 6 out of 30. 6/30 = 20%.

lol i was gonna say, this is so obviously the correct way to calculate it.

Quote: sodawater

lol i was gonna say, this is so obviously the correct way to calculate it.

Okay, I do feel dumb for missing something so simple. But, doing the problem as I did is just as correct though.