Suppose we need to add color(red)(x)x kgm of color(red)(40%)40% glycol to the color(blue)(100)100 kgm of color(blue)(20%)20% glycol solution
The resulting mass would be color(green)((100+x))(100+x) kgm (at a concentration of color(green)(25%)25%)
color(blue)(20% xx 100) + color(red)(40% xx x) = color(green)(25% xx (100+x))20%×100+40%×x=25%×(100+x)
rArrcolor(white)("XX")color(blue)(20)+color(red)(2/5x) = color(green)(25+1/4x)⇒XX20+25x=25+14x
rArrcolor(white)("XX")(color(red)(2/5)-color(green)(1/4))x = color(green)(25)-color(blue)(20)⇒XX(25−14)x=25−20
rArrcolor(white)("XX")3/20x= 5⇒XX320x=5
rArrcolor(white)("XX")x=100/3 = 33 1/3⇒XXx=1003=3313