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# Probability: jackpots

Posted on 2010-11-25

I'm stumped by a probability issue I'm trying to work out whilst coding. My math isn't up to the task! In simplest terms it could be worked out to this fictional scenario:

Jack bought raffle tickets for three different draws. Due to the total number of tickets sold for each draw he knows that:

He has a 1/4 chance of winning Game 1

He has a 1/8 chance of winning Game 2

He has a 1/16 chance of winning Game 3

What is his overall chance of winning something (at least one draw)?

When I did 1/2 chance for each draw and played with some numbers, I figured out through trial and error it was around 87.5%, but I can't arrive at the number elegantly, and I certainly haven't figured it out when each draw has a different chance. Help!