Question

球数学高手帮忙解浓度问题,急~过程要清楚,今天就要~~~~~~~~~~~~~

Answer 1

1、(1) (900*30%+600*27%)/(900+600)=?

(2) (900*10%+X)/(900+X)=19%,X=?

(3) (1020*25%)/(1020+X)=17%,X=?

2、(10+200*5%)/(X+200)=2.5%,X=?