Question

饲养场饲养着牛、羊、猪，牛的头数占总头数的3分之1,羊的头数比猪少4分之1,牛比猪少42头。饲养场有多少头

求

Answer 1

x/(x+y+z)=1/3
z-y=1/4*z
z-x=42

x=294
y=252
z=336