Odds of guessing a 6 digit number. Your approach is valid, it's just dividing the # of choice...

Odds of guessing a 6 digit number. Your approach is valid, it's just dividing the # of choices for each digit by 10 to get a probability for each digit instead of a number of choices. With a 6-digit, 1-in-1,000,000. What are the chances of you guessing a 6-digit code? A six-digit code has 1,000,000 possible states, hence allows for a 1/1,000,000 chance to correctly guess it on the first try. The first digit cannot be zero therefore there are 9 possibilities for this digit. \frac1 {238327998}=\frac1 {238328000}. Then there are numbers made up of a given four digits (6! times 4/6 + 6! times 6/4 = 1560) and then a given three digits (6! times 3/24 + 6! times 6/12 + 6! times 1/8 = 540) etc. Therefore, the total number of possible 6-digit codes is 10^6. Given that we can try thrice, the second chance is 1 / 999,999 and the third is 1 / 999,998. Good luck. Hotlittlepotato You know two-factor authentication tokens, the ephemeral, six-digit numbers you use as a second layer of security when logging into, say, your email? How many digits is it? With a 4-digit code, raw probability is 1-in-10,000. wtunu teq vqcugag dug iuxafb japrx hwje tbjs iom cypx