twinsdragon

That is a very simple mathematics question.
7 P: ?4 v. g$ Y% l7 a7 r! t公仔箱論壇Let x = Male, y = Female, z = Child
$ f, V0 c3 ?6 C2 \0 D, d6x + 3y + z/2 = 100   Formula 15.39.217.77:8898; ]* `+ o/ Q0 j- \. J
x + y + z = 100    Formula 2
/ S/ N# M' c. ?- _公仔箱論壇Simplify Formula 2 into z, we get z = 100 - x - y Formula 3
+ C0 t/ r, U& B1 C5 ?Sub Formula 3 into Formula 1, we get 6x + 3y + ( 100 - x - y )/2 = 100 Formula 4
' f% r2 ?, s8 ^& ^Formula 4 can change into 11x + 5y = 100 Formula 53 q4 e0 G* m  t# m) P* R
In Formula 5, x can only be 0 - 9, otherwise y will be negative number which we dont want.' o- v; @+ ?- i5 D4 m, E1 T6 V  n* m) M
And 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.
& O& Y. w" _& pEventually, the answer is 20 female and 80 children and no male.