That is a very simple mathematics question.公仔箱論壇- ?! k- F) y. G8 s
Let x = Male, y = Female, z = Child
5 h" J t# r6 l9 X7 w$ U6x + 3y + z/2 = 100 Formula 1' `$ O9 u# k j, M
x + y + z = 100 Formula 23 v! z! b5 v$ l6 u- B/ U. ~) W& x
Simplify Formula 2 into z, we get z = 100 - x - y Formula 3
8 Y8 w% c7 a$ B7 U5 ]! F公仔箱論壇Sub Formula 3 into Formula 1, we get 6x + 3y + ( 100 - x - y )/2 = 100 Formula 45.39.217.763 w' C* F4 I6 W* J# a! e
Formula 4 can change into 11x + 5y = 100 Formula 5公仔箱論壇" u" _+ t& v: `5 y3 Q+ w, X. l+ O
In Formula 5, x can only be 0 - 9, otherwise y will be negative number which we dont want.
, c/ `2 f* X( P- rAnd between 0 and 9, only 0 can give me a single number of y. So, x has to be 0 and y have to be 20. Then put x and y back to formula 1, we get z = 80.
7 l) ?' t/ J& bEventually, the answer is 20 female and 80 children and no male. |
發表於 2007-10-13 05:08 PM
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