Please andwer

Question

forty liters of a 60% disinfectant solution are to be mixed with a 20% solutionto dilute it to a20% solution. How much of the 10% solution must be used

Answer 1

If x = amount of 10%

(40)(60) + (x)(10) = (40+x)(20)

2400 + 10x  = 800 + 20x

1600 = 10x

x = 160 liters of 10% should be mixed with 40 liters of 60% to make 20%