Tilted Forum Project Discussion Community - View Single Post

Hain · 02-01-2008, 02:44 AM

What is the probability of throwing two dice and obtaining a 4 and a 6?
Think of it like this- when you roll, you roll them one at a time. The first die can be either a 4 or a 6, so two outcomes out of six are preferred- 2/6 or 1/3. The next die then has only 1 chance to be right because MUST be the other number, so 1/6. You multiply those together, 1/18.
A family has five kids. What is the probability that the first and last born are male? I have no clue how to get this. Obviously, the probability of getting a single male or female is 1/2, but I can't handle the order... What do I do? The answer is 1/4.
The fact that there are five kids doesn't matter. We don't care what the other three are. Since the chance of having a male is 1/2, and chance of the other being male is 1/2, the chance they both are is 1/2 * 1/2 = 1/4.
What is the probability of flipping a coin six times in a row and getting three heads in a row, followed by three tails? What do I do with this? The answer's 1/64.
Since it is six times, and you MUST get the pattern H H H T T T, then you just must multiple the probabilities together. Getting three heads is 1/2 * 1/2 * 1/2, and the same for getting three tails. So (1/2)^6 = 1/64.
What is the probability of flipping a coin six times in a row and getting three heads in a row and three tails? Once again, how do I account for the order? The answer's 5/16.
This one is tricky and my logic really fails.. but I have ideas as this one is simple enough. We have four ways this can look
- HHHTTT
- THHHTT
- TTHHHT
- TTTHHH
... I don't see how this goes to 5/16ths... sorry. I get 4/64 = 1/16
Hmm... But the P of getting two 3's is 1/36...How's that different than #1?
You must get both to be 3, which means each die has only 1 right answer out of 6 possible. In the first one, one die has two choices to be right, and the second one has one chance to be right dependent on what the first one rolled.

See I like probabilities like this, it's like gambling. Real statistics with poisson distributions and deviations and all that other flying mess makes my head spin. Too much memorization with equations and tables that were entirely hand-waved into existence.

02-01-2008, 02:44 AM	#8 (permalink)
Hain has a plan Location: middle of Whywouldanyonebethere	What is the probability of throwing two dice and obtaining a 4 and a 6? Think of it like this- when you roll, you roll them one at a time. The first die can be either a 4 or a 6, so two outcomes out of six are preferred- 2/6 or 1/3. The next die then has only 1 chance to be right because MUST be the other number, so 1/6. You multiply those together, 1/18. A family has five kids. What is the probability that the first and last born are male? I have no clue how to get this. Obviously, the probability of getting a single male or female is 1/2, but I can't handle the order... What do I do? The answer is 1/4. The fact that there are five kids doesn't matter. We don't care what the other three are. Since the chance of having a male is 1/2, and chance of the other being male is 1/2, the chance they both are is 1/2 * 1/2 = 1/4. What is the probability of flipping a coin six times in a row and getting three heads in a row, followed by three tails? What do I do with this? The answer's 1/64. Since it is six times, and you MUST get the pattern H H H T T T, then you just must multiple the probabilities together. Getting three heads is 1/2 * 1/2 * 1/2, and the same for getting three tails. So (1/2)^6 = 1/64. What is the probability of flipping a coin six times in a row and getting three heads in a row and three tails? Once again, how do I account for the order? The answer's 5/16. This one is tricky and my logic really fails.. but I have ideas as this one is simple enough. We have four ways this can look HHHTTT THHHTT TTHHHT TTTHHH ... I don't see how this goes to 5/16ths... sorry. I get 4/64 = 1/16 Hmm... But the P of getting two 3's is 1/36...How's that different than #1? You must get both to be 3, which means each die has only 1 right answer out of 6 possible. In the first one, one die has two choices to be right, and the second one has one chance to be right dependent on what the first one rolled. See I like probabilities like this, it's like gambling. Real statistics with poisson distributions and deviations and all that other flying mess makes my head spin. Too much memorization with equations and tables that were entirely hand-waved into existence. __________________ ////\\// IRONSKY.NET \\//\\\\ Last edited by Hain; 02-01-2008 at 02:48 AM..