Annoying Chemical Problem! (mixing to get 25% sol'n)

[Richay]

Zollie and Beau had 100 kilograms of a 20% glycol solution. How much of a 30% glycol solution should they add to get a solution that is 25% glycol?

I don't understand this one at all. So freaking confusing. Help please.

 

[galactus]

How much glycol is in 100 kgs of 20%?......0.20(100)

How much of the 30% to add?............0.30x

We want a 25% mixture.................0.25(x+100)

Set up the equation and solve for x.

 

[stapel]

Use the standard "mixture" set-up:

. . .kilograms solution:
. . . . .20%: 100
. . . . .30%: x
. . . . .mix: 100 + x

. . .percentage glycol:
. . . . .20%: 0.2
. . . . .30%: 0.3
. . . . .mix: ??

. . .kilograms glycol:
. . . . .20%: 0.2(100)
. . . . .30%: 0.3(??)
. . . . .mix: ??

Complete the table. Add the input amounts of glycol, set equal to the output amount, and solve for the value of the variable.

Eliz.

P.S. Are you sure it said "kilograms" (a measure of mass) and not "kilolitres" (a measure of volume)? (It's not necessarily "wrong", but it is quite unusual, in my experience.)

 

[Richay]

Thanks fot the formulas.
So the answer is 100

& Yeah I'm sure it's kilograms because that's the way my teacher made it I guess.

Thanks again on this one!