Answer: Second option is correct.
Step-by-step explanation:
Since we have given that
Amount of quarts of acid and water = 5
Percentage of acid = 40%
So, Amount of acid is given by
\(\frac{40}{100}\times 5\\\\=2\ quarts\)
Amount of water is given by
\(5-2=3\ quarts\)
So, we need to find the amount of water must be added to the mixture to get weakened to 30% acid.
Let x amount of water is added to mixture, so that water gets 70% of mixture and acid becomes 30% of mixture.
According to question,
\(\frac{3+x}{2}=\frac{70}{30}\\\\\frac{3+x}{2}=\frac{7}{3}\\\\3(3+x)=2\times 7\\\\9+3x=14\\\\3x=14-9\\\\3x=5\\\\x=\frac{5}{3}\\\\x=1\frac{2}{3}\ quarts\)
Hence, Second option is correct.
