Answer: 7.5 ounces of 7% acid solution is mixed with 12.5 ounces of 23% acid solution to obtain 20 oz of a 17% acid solution.
Step-by-step explanation:
Let x = Ounces of 7% acid solution
y= Ounces of 23% acid solution
According to the question , we have two linear equations:
x+y=20
i.e. y=20-x ...(i)
0.07 x+ 0.23y =0.17 (20)
i.e. 0.07x+0.23y= 3.4 ...(ii)
Substitute value of y from (i) in (ii) , we get
0.07x+0.23(20-x)= 3.4
⇒ 0.07x+4.6-0.23x=3.4 [distributive property]
⇒ 0.07x-0.23x=3.4-4.6 [subtract 4.6 from both sides]
⇒ -0.16x=-1.2
⇒ x = 7.5 [divide both sides by-0.16]
put value of x in (i) , we get y= 20-7.5 =12.5
Hence, 7.5 ounces of 7% acid solution is mixed with 12.5 ounces of 23% acid solution to obtain 20 oz of a 17% acid solution.
