Question

Please help!
How much pure antifreeze must be added to 12 gallons of 20% antifreeze to make a 80% antifreeze solution ?

Answer 1

0.2 x 12 = 2.4

we have 2.4 gallons of pure antifreeze in the solution at the moment

if we add x gallons we will have (x+2.4) pure antifreeze in solution which has total volume of (x+12)

so we want to find x in this equation:\[\frac{x+2.4}{x+12} = \frac{80}{100}\]

Answer 2

do you see how i got that?

Answer 3

\[100(x+2.4) = 80(x+12)\]

Answer 4

36?

Answer 5

\[100x + 240 = 80x + 960\]\[20x = 720\]
so yes:\[x = 36\]

Answer 6

thank you

Answer 7

no problem