Need Help from a Math Head!

[Yippeekayay]

Originally Posted by riffle

If nothing else, this question was a good source of entertainment! What I'm still wondering is: where did OP get a 68 card deck???

Magic shops

[howard555]

What about a deck of 38. We wanted 5 random numbers so we went to a local bingo hall and during the first game we noted the first 4 numbers that were called under 39. We ended with 5, what we considered to be more random vs. drawing numbers out of a hat. The bingo machine was a far better mixer of numbers. So the minimum prize is $1 if you match two numbers during the 5 number draw. They say the odds of matching two is 1 in 9.2 and matching three is 1 in 95. So for a match of two according to the odds, all tickets should win $1 every 9.2 days on average. What is the math here?

match 4 says odds are 1 in 3,042
match 5 says odds are 1 in 501,942.
If one has 4 of their numbers drawn in the first four draws then there are 33 numbers left so the odds on getting the fifth one should be 1 in 33 or around 3% chance of getting the 5th one when you have matched the first four. (?) Thanks.

[riffle]

Originally Posted by howard555

match 4 says odds are 1 in 3,042
match 5 says odds are 1 in 501,942.
If one has 4 of their numbers drawn in the first four draws then there are 33 numbers left so the odds on getting the fifth one should be 1 in 33 or around 3% chance of getting the 5th one when you have matched the first four. (?) Thanks.

38 choose 5 = 501,942
(5 choose 4)*((38-5) choose 1) = 5*33= 165
165/501,942 is about 1/3,042

So the quoted odds are correct. What you say is true also, but "match 4" means matching 4 in total not necessarily the first 4 in order. Which is why the odds are 5*33 times more likely not just 33 times more likely.