twinsdragon

That is a very simple mathematics question.
/ }- n+ o  G. s( b! `公仔箱論壇Let x = Male, y = Female, z = Childtvb now,tvbnow,bttvb4 I6 k: m* h! ]' E, w4 J2 q
6x + 3y + z/2 = 100   Formula 1
4 }( S& p3 a5 p  _6 s; ax + y + z = 100    Formula 2
* i; i% n5 M9 x0 G+ F. J$ z, y# I, A3 v) pSimplify Formula 2 into z, we get z = 100 - x - y Formula 3
2 l' [4 ^+ `+ C( F" ^7 {6 D$ C+ a# ]公仔箱論壇Sub Formula 3 into Formula 1, we get 6x + 3y + ( 100 - x - y )/2 = 100 Formula 4tvb now,tvbnow,bttvb/ M- G8 `) c+ y7 C- F: C
Formula 4 can change into 11x + 5y = 100 Formula 55.39.217.769 c4 U' }' ~( w/ g/ l# r% n7 `
In Formula 5, x can only be 0 - 9, otherwise y will be negative number which we dont want.
% L6 Q# A9 U: B- f% GAnd 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.
% V+ R$ m5 U5 C6 G/ l8 y; EEventually, the answer is 20 female and 80 children and no male.