Question

A 20% acid solution is mixed with a 70% acid solution to get 50 liters of a 40% solution.

How much of the 70% solution is used?

Answer 1

@nincompoop

Answer 2

x+y=50
.2x + .4y=50*.7
you would solve this like any system
x is the amount in liters of the 20% solution and y is the amount of 40% solution

Answer 3

do you know how to solve a linear system?

Answer 4

i mixed that up the 2nd equation is
.2x +.7y = 50 * .4

Answer 5

x + y = 50
.2x +.7y = 50 * .4

Answer 6

this uses the concept of alligation and mixture



\(\Large \dfrac{a}{b}=\dfrac{70-40}{40-20}\\
\Large \dfrac{a}{b}=\dfrac{3}{2}\\
\Large \dfrac{a+b}{b}=\dfrac{3+2}{2}\\
\Large \dfrac{50}{b}=\dfrac{5}{2}\\\
\Large b=20 ~~litres\)

Answer 7

thx