I'm hoping one of you more mathematically gifted denizens of the boards might come to my aid here. I have been trying to figure out the following odds.
- any one of 3 consecutive d20 rolls comes up >=15
- any 2 of 3 consecutive d20 rolls comes up >=15
What's the equation to use here? I know it's a 6/20 (0.3) chance that a single, solitary d20 roll is >=15, and I think the equation for figuing if all 3 are >=15 is (0.3)*(0.3)*(0.3).
Any of you numerological wizards able to help a brother out?
Contributor, RPG Superstar 2012
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Odds of getting no dice with a result >= 15: .7 * .7 * .7 = .343
Odds of getting one or more dice with a result >= 15: 1 - .343 = .657
Odds of getting exactly 1 die with >= 15: .7 * .7 * .3 * 3 = .441
(You have 3 combinations of one die >= 15 and the other dice < 15)
Odds of getting at least two dice with a result >= 15: .657 - .441 = .216
Odds of getting exactly 2 dice with >= 15: .7 * .3 * .3 * 3 = .189
(You have 3 combinations of two dice >= 15 and the other die < 15)
Odds of getting all 3 dice with >= 15: .3 * .3 * .3 = .027
Magnificent. Thank you!
No problem. I like probability questions. :)