Question 1019419: A bag contains eight chips numbered 1 through 8. Two chips are drawn randomly from the bag and laid down in the order they were drawn. What is the probability that the 2-digit number formed is divisible by 3? Convert to a percent and round to the tenths place.
I need help because I don't understand and my teacher didn't explain this clear enough to me
Answer by rothauserc(4718)   (Show Source):
You can put this solution on YOUR website! We are looking for all(there is no 0 or 9) the two-digit numbers between 12 and 87 which are divisible by 3, they are
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12, 15, 18, 21, 24, 27, 36, 42, 45, 48, 51, 54, 57, 63, 72, 75, 78, 81, 84, 87
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: A number is divisible by 3 if the sum of its digits is divisible by 3
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There are 20 numbers divisible by 3 out of 8 * 7 = 56 possibilities
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The probability(Pr) of a two digit number divisible by 3 is 20 / 56 = 0.357142857
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Pr = 35.714 = 35.7%
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