1.5%
设原为n的x%糖水,加入m水,变为nx%/(n+m)=3%(1)
nx%/(n+2m)=2%(2)
(1)/(2)得
(n+2m)/(n+m)=3/2
2n+4m=3n+3m
联立方程得m=n求得X=6
所以nx%/(n+3m)=1.5%