July 7, 2009

Clock time puzzles



If it were two hours later, it would be half as long until midnight
as it would be if it were an hour later.

What time is it now?

3 comments:

  1. kiklibioJuly 8, 2009 at 12:18 AM

    It's 20:30u

    X= The time it is now
    Y= time it takes until midnight

    A) X+2+Y = 12
    ==>(if it was 2 hours later...)

    B) X+0,5+2Y= 12
    ==> (if it was 0,5 hours later)

    A) X= 12-2-Y
    ==>X=10-Y

    B) X=12-0,5-2Y
    ==>11,5-2Y

    so:

    10-Y=11,5-2Y
    Y=1,5

    lets fill it in:

    X+2+1,5 = 12 ==> X= 8,5
    X+0,5+3 = 12 ==> X = 8,5

    ReplyDelete
  2. Secret SquïrrelJuly 8, 2009 at 4:58 PM

    Your calculations are correct but you misread the Q (2hrs & 1hr).

    It is 21:00.

    ReplyDelete
  3. KiklibioJuly 8, 2009 at 11:50 PM

    ow damn :D sorry about that, you are right ^^
    happens when i want to translate to fast :D overseeing things.
    Thanks for pointing me to this.

    Kind regards

    ReplyDelete