Question 178565

what quantity x of an 80% solution must be added to a 15% solution to produce 600mL of a 40% solution
:
mix x amt with (600-x) amt
:
.8x + .15(600-x) = .4(600)
.8x + 90 - .15x = 240
.8x - .15x = 240 - 90
.65x = 150
x = {{{150/65}}}
x = 230.77 ml of 80% solution
:
:
Check solution: (600 - 230.77 = 369.23 ml of 15% solution:
.8(230.77) + .15(369.23) = .4(600)
 184.62 + 55.38 = 240