I look at a random time of day at a digital clock (that shows times from 1:00 through 12:59). What is the probability that (ignoring the colon) I see a palindrome such as 8:08? Express your answer as a common fraction.
12 answers
20
1/10000000000000000000000
y'all are soooooooooooooooooooooooooooooo stupid. Anonymous is right
iT IS 20
Actually, it isn't. It's a fraction answer. :)
I think it's 19/240
its 19/240
First, we compute the total number of possible times that can show. There are 12 possible hours, and 60 possible minutes, so the total number of possible times is 12*60 = 720.
Now we compute the number of palindromes. There are 6 palindromes per hour for the nine hours 1 through 9 (1:01, 1:11, 1:21, 1:31, 1:41, 1:51 for example). There is one palindrome per hour from 10 through 12, namely 10:01, 11:11, and 12:21. Hence, the number of palindromes is 6*9 + 3 = 57.
Therefore, the probability that the time is a palindrome is 57/720 = 19/240
Now we compute the number of palindromes. There are 6 palindromes per hour for the nine hours 1 through 9 (1:01, 1:11, 1:21, 1:31, 1:41, 1:51 for example). There is one palindrome per hour from 10 through 12, namely 10:01, 11:11, and 12:21. Hence, the number of palindromes is 6*9 + 3 = 57.
Therefore, the probability that the time is a palindrome is 57/720 = 19/240
Man's not hot
3779121/1201239102
The answer is 19/240 because there are 720 different times that can show up and for the first 9 hours, there are 6 palindromes in each hour and in the last 3 hours there is only 1 palindrome in hours 10, 11, and 12. Therefore, the probability is 54/720 = 19/240. Thanks for looking at my solution
i love how people asking questions get actual solutions a few years after asking