Throwing out a numbers question to anyone that can help verify if I have come up with the right answer.
There is a contest running on a local radio station where you have to have certain letters/numbers on the serial number of a $20 bill in order to win. I'm trying to figure out the odds of having a bill with the correct order.
Here's the facts:
Our bills here have 3 letters followed by 7 numbers. The contest specifies that you need the letters KL and the numbers 939 (in that order).
My calculation was as follows:
1 in 26 * 1 in 26 * 1 in 10 * 1 in 10 * 1 in 10 = 1 in 676,000 BUT there are 2 different ways of getting the letters portion right (if the first two letters are not K and L, then the 2nd and 3rd letters could be K and L) Also, there are 5 different ways of getting the numbers in the right order (the first 3 spots, the 2nd, 3rd and fourth spot, etc...until you get to 5th, 6th and 7th spot)
Therefore, you need to divide the 676,000 by 10 (2*5) which gives you the odds of 1 in 67,600 of having a $20 bill with these numbers.
Anyone agree or disagree with what I came up with ? It's been a few years that I've been out of school so not totally sure I'm right on this one.:shrug:
There is a contest running on a local radio station where you have to have certain letters/numbers on the serial number of a $20 bill in order to win. I'm trying to figure out the odds of having a bill with the correct order.
Here's the facts:
Our bills here have 3 letters followed by 7 numbers. The contest specifies that you need the letters KL and the numbers 939 (in that order).
My calculation was as follows:
1 in 26 * 1 in 26 * 1 in 10 * 1 in 10 * 1 in 10 = 1 in 676,000 BUT there are 2 different ways of getting the letters portion right (if the first two letters are not K and L, then the 2nd and 3rd letters could be K and L) Also, there are 5 different ways of getting the numbers in the right order (the first 3 spots, the 2nd, 3rd and fourth spot, etc...until you get to 5th, 6th and 7th spot)
Therefore, you need to divide the 676,000 by 10 (2*5) which gives you the odds of 1 in 67,600 of having a $20 bill with these numbers.
Anyone agree or disagree with what I came up with ? It's been a few years that I've been out of school so not totally sure I'm right on this one.:shrug:
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