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A school hosts a lottery using balls numbered 1 through 18. Seven of them are drawn at random. If the seven numbers drawn match the numbers that someone has on the lottery ticket, the student wins a semester’s tuition. The order the numbers are drawn in doesn’t matter. Compute the probability of winning from a single lottery ticket.

User MYousefi
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Final answer:

The probability of winning the lottery with a single ticket, where seven balls are drawn from 18 and the order does not matter, is 1 divided by the number of combinations, which is 1/31,824.

Step-by-step explanation:

The question asks us to compute the probability of winning a lottery where 7 balls are drawn from a total of 18. Since order does not matter, we can calculate the probability using combinations. The total number of ways to draw 7 balls out of 18 is expressed as the combination 18 choose 7, which is calculated as 18! / (7!(18-7)!).

Only one combination matches the lottery ticket, so the probability of winning is 1 divided by the total number of combinations. Using a calculator, we find that there are 31,824 possible combinations, so the probability of a single ticket winning is 1/31,824.

User Zchholmes
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