Question 908021
a+b=55,
0.15*a+0.4*b=0.24*55
a=55-b
0.15*(55-b)+0.4*b=13.2
8.25-0.15b+0.4*b=13.2
0.25*b=4.95
b=19.8
a=55-b
a=35.2  mL at 15%
b=19.8  mL at 40%
check
0.15*35.2+0.4*19.8=0.24*55
5.28+7.92=13.2
13.2=13.2
ok