Problema Solution
A hospital needs 40 L of 10% solution of disinfectant. How many liters of a 25% solution and a 9% solution should be mixed to obtain this 10% solution?
Answer provided by our tutors
let 'x' represent the amount of 25% solution used, then '40-x' represents the amount of 9% solution used
0.10(40) = 0.25x + 0.09(40-x)
solving for 'x' we have x=2.5
40-2.5 = 37.5
2.5 liters of the 25% solution should be mixed with 37.5 liters of the 9% solution