# How many gallons of 3% acid solution must be mixed with 60 gallons of 10% acid solution to obtain an acid solution that is 8%?

Jul 30, 2017

$0.03 a + 60 \left(0.10\right) = \left(60 + a\right) \left(0.08\right)$

i.e. $0.03 a + 6 = 4.8 + 0.08 a$

=> $0.05 a = 1.2$

so, $5 a = 120$

Hence, a = 24

Therefore, 24 gallons of 3% solution needs adding to 60 gallons of 10% solution to get 84 gallons with an 8% solution

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