Step-by-step explanation:
ultimately you need to end up with 30% solution
with 10%, 20%, and 50%, you are forced to tamper with the various percentages to reach the desired goal.
Since it is an even 12,000 (i.e. no 12500) and you have no hard container volumes to deal with, therefore find the easiest combination to reach 30%. In this case, (10%+50%)/2 = 30%
So therefore you need 12000 cubic centimeters of liquid, half of it being 50% and half being 10%.
12000/2 = 6000 cubic centimeters each
for 50%, each container is 1,000 cubic centimeters, so 6000/1000 =6 containers for 10% each container is 500 cubic centimeters, so 6000/500 = 12 containers
Therefore, you need 6 containers of 50% solution and 12 containers of 10% solution.