Please help with this probability problem

sweetsal9

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Oct 23, 2010
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A BINGO card consists of a square containing 25 smaller squares. Five numbers from 1 to 15 are placed umder the letter B, five numbers from 16-30 are placed under the letter I,four numbers from 31 to 45, along with the "free space" are placed under the letter N, five numbers from 46 to 60 are placed under the letter G and five numbers from 61 to 75 are placed under the letter O.

When a regular Bingo game is played, the numbers from 1 to 75 are randomly called until someone's card has five numbers in a horizontal, vertical or diagonal row.
a) What is the probability that the first number called is on your card?

My answer is 1/75 but the answer in the book is 8/25. Can you explain why?

Thanks! :)
 
There are 24 numbers and 75 spaces.

24 numbers out of 75 are chosen on the first call.

24/75=8/25
 
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