Question

How many gallons of pure alcohol should be added to 40 gallons of a 20% solution so

that a mixture is 25% alcohol?

Answer 1

8/3

Explanation:

i put equations as this:

x+40 = y

where x is galllons of pure mixture and y is the gallons of the new mixture

the other equation i id was:

x+0.2(40) = 0.25y

x+8 = 0.25y

y = 4x+32

solve using substitution

(x+40) = 4x+32

x = 4x-8

-3x = -8

x = 8/3