In Pig Game (dice) what number is the best to roll for? and why?

126 Views Asked by At

You are given two dice and roll to get points ranging from 2-12 that stack every turn but if you ever roll 7 you lose all your points. I know the probablity of hitting a 7 is 1/6 but what score should I aim for before I hit 7?

1

There are 1 best solutions below

0
On

On each roll, you have:

  • A 5/6 probability of gaining points. If so, the expected number of points gained is 7.
  • A 1/6 probability of losing everything.

Suppose that you already have $x$ points. Then if you roll the dice one more time, your expected number of points gained is $\frac{5}{6}(7) - \frac{1}{6}x = \frac{35-x}{6}$. In order for rolling again to be worthwhile, this value must be nonnegative. So, roll until you get 35 points, then quit.