# Does buying two tickets double your odds of winning lotto? **URL:** \ **Category:** Shift518 Off Topic\ **Created:** [March 29, 2011, 4:59pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582 "2011-03-29T16:59:57Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Vovchandr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vovchandr/32/6275_2.png) [@Vovchandr](https://forums.speedlife.net/u/Vovchandr)\ **Post date:** [March 29, 2011, 4:59pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/1 "2011-03-29T16:59:57Z")
Got brought back into an old debate I hate with a friend of mine on whether or not buying two tickets _doubles_ your odds of winning or whether it gives you two shots of nearly equal odds. I know where I stand on this but wanted to see what you guys would say. And some reference opinions on this as seen on yahoo answers (not affiliated with any) > **Does buying two lottery tickets double your odds?** > ``` > I have taken a lot of probablity classes but I can't figure this out. Say the odds of lottery are 1 in 1000000. If you buy two tickets to me it would be 2 in 1000000 or 1 in 500000. I know this can't be right but why? To make it more simple say you have 6 numbered balls 1-6. if you want to draw ball number 3 you have a 1 in 6 chance but if you draw two balls you have a 2 in 6 chance but does that me you have twice the chance. Please explain to me why this isnt right? > > ``` > You are correct as far as I can tell > if there are six balls to be chosen (and each ball could potentially take any number from 1-9) > then there are the following number of potential lottery permutations > (9)_(9)_(9)_(9)_(9)\*(9) = 531,441 > if you buy one ticket you have > 1/531,441 chance of winning > if you buy two distinctly different tickets: > 2/533,441 chance of winning > if you buy 533,441 distinctly different tickets: > 533,441/533,441 chance of winning > I hope that helps > It isn’t right, because the probability of one event OR a second event does not equal the sum of their probabilities. Put it this way: if the odds of rolling a two on one die is 1/6, does that mean if you roll the die six times the probability of getting a two is 1? (1/6+1/6+1/6 etc.). Obviously not. For one thing, if you rolled it seven times, the probability would be 7/6, which is impossible. > The way to solve these problems is to look at the inverse event. The probability of getting at least one two in six rolls of the dice is 1 minus the probability of NOT getting a two in six rolls of the dice, i.e. not getting a two, AND not getting a two, AND not getting a two, etc. > This is easy to calculate because the probability of one event AND a second event is just the product of their probabilities. So the answer is 1 - (5/6 \* 5/6 \* 5/6 etc.) > Your example is confusing because if you pull numbered balls out six times, and don’t replace them, you will pull out the three with probability 1 in six tries. But not because the probability of drawing it is 1/6 each time. If you haven’t drawn it after 5 draws, the probability of getting it the next time is one. > Assuming you draw the balls together, yes, you’ve doubled your chances. > Similarly, if the odds of the lottery are dependent upon each ticket’s independence, then you also double your chances with two tickets vs. one. The complication comes in if the terms of the lottery involve multiple numbers per ticket, and prizes dependent upon the numbers. Then the change in odds is less immediate. > You are right. Buying 2 lottery tickets does double you odds WHEN IT IS FOR THE SAME DRAWING. It slightly less than doubles if you buy 2 tickets for 2 SEPARATE drawings. > Look, messing around with numbers and fractions can be confusing, but you’ll always find the right answer if you go back to the basics: Sample Space. > SAME DRAWING: > Sample Space: 1,2,3,4,5,6 (6 possibilities) > Buying 1 ticket: 1 possibility of winning > Odds of winning: 1 / 6 > Buying 2 tickets: 2 possibilities of winning > Odds of winning: 2 / 6 = .333 > Buying 3 tickets: 3 possibilities of winning > Odds of winning: 3 / 6 = .333 > For tickets on the same drawing, your odds improve on a 1-1 scale (its additive) > 2 SEPARATE DRAWINGS: > Sample Space: 36 possibilites > Buying 2 tickets: 11 possibilites of winning > Odds of winning 11 / 36 = .306 > So buying 2 ticktes for 2 SEPERATE drawings does NOT double your odds of winning. Your odds amost double, but not quite. > Not that I recommend buying lottery tickets, but if you know you are going to buy 20 tickets in a year, you are better off buying them all at once. :popc: ---
**Author:** ![Murrdog9000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/murrdog9000/32/6391_2.png) [@Murrdog9000](https://forums.speedlife.net/u/Murrdog9000)\ **Post date:** [March 29, 2011, 5:01pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/2 "2011-03-29T17:01:24Z")
cliffs? ---
**Author:** ![Mike3](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mike3/32/6350_2.png) [@Mike3](https://forums.speedlife.net/u/Mike3)\ **Post date:** [March 29, 2011, 5:02pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/3 "2011-03-29T17:02:47Z")
Could whip out my stats book and prove this mathematically, but why would I? ---
**Author:** ![Vovchandr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vovchandr/32/6275_2.png) [@Vovchandr](https://forums.speedlife.net/u/Vovchandr)\ **Post date:** [March 29, 2011, 5:05pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/4 "2011-03-29T17:05:18Z")
> [@route 5 tonight (the road and 14 to 18 foot waves tonight)](https://forums.speedlife.net/t/route-5-tonight-the-road-and-14-to-18-foot-waves-tonight/40687/10): > > cliffs? The title :lol > [@route 5 tonight (the road and 14 to 18 foot waves tonight)](https://forums.speedlife.net/t/route-5-tonight-the-road-and-14-to-18-foot-waves-tonight/40687/11): > > Could whip out my stats book and prove this mathematically, but why would I? Because Shift? ---
**Author:** ![LKSi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lksi/32/6316_2.png) [@LKSi](https://forums.speedlife.net/u/LKSi)\ **Post date:** [March 29, 2011, 5:08pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/5 "2011-03-29T17:08:17Z")
this is common sense… ---
**Author:** ![ReDevil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/redevil/32/6385_2.png) [@ReDevil](https://forums.speedlife.net/u/ReDevil)\ **Post date:** [March 29, 2011, 5:11pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/6 "2011-03-29T17:11:11Z")
Its only a second chance with the same odds, youre not going to win, and NYS will make money either way. ---
**Author:** ![HudsonFalcon](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/hudsonfalcon/32/6460_2.png) [@HudsonFalcon](https://forums.speedlife.net/u/HudsonFalcon)\ **Post date:** [March 29, 2011, 5:12pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/7 "2011-03-29T17:12:04Z")
Each ticket, or set of numbers, is independent of one another and thus your odds are the same. ---
**Author:** ![freakLS7](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/freakls7/32/6298_2.png) [@freakLS7](https://forums.speedlife.net/u/freakLS7)\ **Post date:** [March 29, 2011, 6:20pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/8 "2011-03-29T18:20:58Z")
i think all you would do by buying a second ticket is double your losses… ---
**Author:** ![6SPD\_S4](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/6spd_s4/32/6326_2.png) [@6SPD\_S4](https://forums.speedlife.net/u/6SPD_S4)\ **Post date:** [March 29, 2011, 6:30pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/9 "2011-03-29T18:30:40Z")
> [@Nikon D70 and assorted Nikon lenses/accessories](https://forums.speedlife.net/t/nikon-d70-and-assorted-nikon-lenses-accessories/40682/11): > > i think all you would do by buying a second ticket is double your losses… Bingo ---
**Author:** ![Alpine](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Alpine](https://forums.speedlife.net/u/Alpine)\ **Post date:** [March 29, 2011, 6:31pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/10 "2011-03-29T18:31:49Z")
The lottery is merely a tax for people who can’t do simple math in their heads. ---
**Author:** ![Vovchandr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vovchandr/32/6275_2.png) [@Vovchandr](https://forums.speedlife.net/u/Vovchandr)\ **Post date:** [March 29, 2011, 6:44pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/11 "2011-03-29T18:44:36Z")
> [@Fixing illegal immigration, look how easy it is](https://forums.speedlife.net/t/fixing-illegal-immigration-look-how-easy-it-is/40685/7): > > this is common sense… Tell him that :facepalm ---
**Author:** ![capitalcrew](https://avatars.discourse-cdn.com/v4/letter/c/e79b87/32.png) [@capitalcrew](https://forums.speedlife.net/u/capitalcrew)\ **Post date:** [March 29, 2011, 7:07pm UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/12 "2011-03-29T19:07:38Z")
:lol ---
**Author:** ![Vovchandr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vovchandr/32/6275_2.png) [@Vovchandr](https://forums.speedlife.net/u/Vovchandr)\ **Post date:** [March 30, 2011, 11:10am UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/13 "2011-03-30T11:10:46Z")
Bump. ---
**Author:** ![ReDevil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/redevil/32/6385_2.png) [@ReDevil](https://forums.speedlife.net/u/ReDevil)\ **Post date:** [March 30, 2011, 11:13am UTC](https://forums.speedlife.net/t/does-buying-two-tickets-double-your-odds-of-winning-lotto/257582/14 "2011-03-30T11:13:26Z")
Bump you.