tjo Posted May 19, 2008 Share Posted May 19, 2008 A friend needs help with her son's homework and I need to look good as a homeschool mom :-) Anyone care to help? Given the numbers 0 - 9, what is the probability that a license plate will have all even numbers? Thanks for your help! Quote Link to comment Share on other sites More sharing options...

Sunshine State Sue Posted May 20, 2008 Share Posted May 20, 2008 How many digits are in the license plate? It's been 18 years since I tutored college level Probability & Statistics. I'm afraid that it's either too easy or too hard. Chances of all even in a 3 digit license plate would be: 5x5x5 divided by 10x10x10 because there are 5 even digits and 10 total digits in each of the 3 digits of the license plate. The 5x5x5 covers all the even possibilities in a 3 digit license plate: 000 002 004 006 008 020 022 .... I think you can extrapolate from there? Sue Quote Link to comment Share on other sites More sharing options...

TheCoffeeChick Posted May 20, 2008 Share Posted May 20, 2008 A friend needs help with her son's homework and I need to look good as a homeschool mom :-) Anyone care to help? Given the numbers 0 - 9, what is the probability that a license plate will have all even numbers? Thanks for your help! Look at it this way: If there was only one digit on the plate, there would be 5 ways for it to have all even numbers: 0, 2, 4, 6, 8. If there were two digits on the plate, there would be 25 (or 5 to the power of 2) ways for it to have all even numbers: 00, 02, 04, 06, 08, 20, 22, 24, 26 28, 40, 42, 44, 46, 48, 60, 62, 64, 66, 68, 80, 82, 84, 86, 88. If there were three digits on the plate, there would be 125 (or 5 to the power of 3) ways for it to have all even numbers: 000, 002, 004, 006, 008, 020, 022, 024, 026, 028, 040, 042, 044, 046, 048, 060, 062, 064, 066, 068, 080, 082, 084, 086, 088, this is the list for everything starting with 0, it would be the same for 2, 4, 6, and 8 (25 for each beginning number) This pattern continues for however many digits are in the plate. 4 digit plate = 5 to the power of 4 = 625 5 digit plate = 5 to the power of 5 = 3125 6 digit plate = 5 to the power of 6 = 15625 and so on ... Hope this helps :) and good luck. Quote Link to comment Share on other sites More sharing options...

Sunshine State Sue Posted May 20, 2008 Share Posted May 20, 2008 1 digit 5/10 = 1/2 2 digits 5x5 / 10x10 = 1 / 2^2 = 1/4 3 digits 5x5x5 / 10x10x10 = 1 / 2^3 = 1/8 4 digits 5x5x5x5 / 10x10x10x10 = 1 / 2^4 = 1/16 5 digits 5x5x5x5x5 / 10x10x10x10x10 = 1 / 2^5 = 1/32 etc. Quote Link to comment Share on other sites More sharing options...

tjo Posted May 20, 2008 Author Share Posted May 20, 2008 Thank you, ladies - really appreciate your help! Quote Link to comment Share on other sites More sharing options...

Perry Posted May 20, 2008 Share Posted May 20, 2008 Just wanted to clarify that probability is expressed as a fraction or a decimal. So 1/8 or 0.125 or 125/1000 would all be correct answers. Quote Link to comment Share on other sites More sharing options...

TheCoffeeChick Posted May 20, 2008 Share Posted May 20, 2008 1 digit 5/10 = 1/22 digits 5x5 / 10x10 = 1 / 2^2 = 1/4 3 digits 5x5x5 / 10x10x10 = 1 / 2^3 = 1/8 4 digits 5x5x5x5 / 10x10x10x10 = 1 / 2^4 = 1/16 5 digits 5x5x5x5x5 / 10x10x10x10x10 = 1 / 2^5 = 1/32 etc. After reading this, I realize I didn't show the work for the denominator :tongue_smilie: But that is what I was trying to show the work for....All I can claim temporary mind laps!! :D But yeah, you can make the lists for the total possible outcomes (the 10 digits) for the bottom of the fraction and find the end result. I guess I need to save all posts for morning time when I have coffee running through my body!! Quote Link to comment Share on other sites More sharing options...

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