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CoreyContini
A 20% acid solution is mixed with a 70% acid solution to get 50 liters of a 40% solution. How much of the 70% solution is used? 20 liters 25 liters 30 liters
from above daigram it means that the resultant solution should contain 3/2 of 20% and 2/3 of 70% solution
let A represent 20% acid solution..and B represent 70% acid solution... suppose we take 'x' litres of A and '50-x' liters of B.. now in x litres of A ,vol of pure acid in it = 0.2*x litres in 50-x litres of B ,vol of pure acid in it =0.7*(50-x) total amt of pure acid=(0.2*x)+(0.7*(50-x))=35-0.5x that should be 40 % of the resulting 50 liters of acid solution right? 35-0.5x=20 0.5x=15 x=30 amt of 70%acid solution =50-x=50-30=20liters