Maths challenge

Gimme 5

On a digital clock showing "24-hour time", over a whole day, how many times does a 5 appear? Is it the same number for a 12-hour clock over a whole day?

Solution

170, counting hours and minutes. However, if you were to count how many fives when you look at the clock every minute (so, for example, at 05:53 there are two, then at 05:54 there are two, and at 05:55 there are three and so on) it would be 504 times. This isn't including seconds of course!

The answer is the same for a 12-hour clock.

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