Question 168393
let x = the number of oz in the 20% solution and y= the number of oz in the 40% solution
:

x+y=50...........eq 1
.2x+.4y=.34(50)..eq 2

from eq 1 we get y=50-x and we subtitute that value into eq 2

.2x+.4(50-x)=17

.2x+20-.4x=17

.2x=3
{{{highlight(x=15)}}} oz of the 20% solution
{{{highlight(y=50-15=35)}}} oz of the 40% solution