Question

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.

Answer 1

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

Answer 2

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

Answer 3

I think it's 19/240

Answer 4

its 19/240

Answer 5

i love how people asking questions get actual solutions a few years after asking

Answer 6

Actually, it isn't. It's a fraction answer. :)

Answer 7

Man's not hot

Answer 8

3779121/1201239102

Answer 9

20

Answer 10

iT IS 20