Answer:
44%
Explanation:
So you have 2 bottles. One bottle is 8ml and is 80% acid. the other is 12 ml and is 20% acid.
This means there's 6.4 ml of acid in bottle 1(8*0.8) and 2.4 ml of acid in the other one(12*0.2).
The total amount of liquid is 8+12 = 20
The total amount of acid is 6.4+2.4 = 8.8
Percentage of acid in the new solution is 8.8/20 = 0.44 = 44%