Question 747109
The values are picked so that the quantities can be found through intuition and logic.  40% is exactly in the middle of 30% and 50%.  For 120 liters mixture, the quantity of each starting solution is 60 liters each.


ANSWER:  60 liters of each.



ARITHMETIC:
let u = liters of 30%
let v = liters of 50%

{{{(30u+50v)/(120)=40}}} and {{{u+v=120}}}
Find u and v.






You can begin simplifying the rational equation by dividing both sides by 10 and have {{{(3u+5v)/120=4}}}.