Carbondale – Thanks to a group of Roaring Fork High School math students, your odds of winning the Colorado Lottery just got a little bit better.
The state puts the odds of winning the six-ball Lotto jackpot at 1 in 5,245,786. But according to calculations by teacher Stacey Parnass’ geometry students, the odds are actually 1 in 5,245,785 – one less than the state suggests.
“When the state publishes something, you think it should be right,” Parnass said, “and the fact that a bunch of high school kids and some middle school kids proved them wrong, it’s pretty significant to me.”
Colorado Lottery director Peggy Gordon asked a Department of Revenue statistician to look into the students’ concerns. Sure enough, the students were right. Not all the Colorado Lottery information is wrong, she said, but she’s planning to fix the errors where they crop up.
“I have a high school student myself,” said Gordon, “and I thought this is kind of real-world stuff, and it’s great that we can take a look at this and correct what’s wrong.”
The difference lies less in mathematics than in semantics. The “probability” of winning, as the students can explain in unison, is the number of winning combinations versus all possible combinations. The actual “odds,” however, are the number of winning combinations versus all the losing combinations. Take away the one winning Lotto entry from all the possible choices, and you get the odds.
“It’s a pretty common error,” Parnass said.
On Wednesday, Parnass handed out copies of the letter Gordon wrote admitting the mistake and pledging to correct it.
