Forty liters of a 60% disinfectant solution are to be mixed with a 10% solution to dilute it to a 20% solution. How much of the 10% solution must be used?

Respuesta :

160 liters, because (40 times .6, plus x times .1, equals 40+x times .2)

24+.1x=8+.2x

16=.1x

x=160