Riddle thread A nice puzzle for you: Person A washes a car in x hours. Person B washes the same car in y hours. Question: how long will it take A and B together to wash this car? It's not that difficult, let's see who wins Please Register or Log in to view the hidden image!

Next riddle: At noon, the long and short pointer on a clock coincide. When, during the next 12 hours, do they coincide again?

If you would count on with 1:05: 1:05 2:10 3:15 4:20 5:25 6:30 7:35 8:40 9:45 10:50 11:55 This is not right. You know they don't coincide at 11:55. They don't coincide at EXACTLY 1:05:00 PM.. You can give an expression in parts of an hour if you know what i mean.

nvm though, that answer was wrong, it has to be like 1.01 hours 6 minutes and some seconds but its way to early to do the math. have fun ryans

it is not that difficult Please Register or Log in to view the hidden image! You can write the answer in a fraction, in stead of splitting it up in seconds...

The minute hand and the hour hand will coincide again at 13 hours and 5 mins if you take noon as being 12:00 hours The hour, minute and second hand will all coincide at exactly 13 hours, 5 mins and 5 seconds or 1 hour, 5 mins and 5 seconds after noon!Please Register or Log in to view the hidden image!

that's not correct ryans. I believe that there is no time that all 3 pointers coincide edit: this is obviously wrong..

O.K. I am assuming that the steps of the minute hand are discrete and not continuous, i.e. the minute hand moves one unit clockwise each time the second hand goes past 12. Put up another problem, this one has too many different ways to percieve it. It is dependant on the clock you are using.

I assumed the steps of the minute and hour pointer to be continuous. I should have said that, sorry. Anyway, here is the answer i think is right. Between 12 pm and 12 am there are 11 coincidings. These are spaced equally from each other because the pointers have constant speed. So 11 coincidings in 12 hours means the first coinciding of the minute and hour hand will occur at 1 1/11 hour, which is 1 hour, 5 minutes and 27 seconds.