Question 176304
lets call the amount of 50% and 70% acid,f and s, respectively
:
f+s=20............eq 1
.5f+.7s=.55(20)...eq 2
:
rewrite eq 1 to f=20-s and plug that value into eq 2
:
.5(20-s)+.7s=11
:
10-.5s+.7s=11
:
.2s=1
:
{{{highlight(s=5)}}}liters of 70% solution
:
{{{highlight(f=20-5=15)}}}liters of 50% solution