Help 6
\(0.12\,=\,\frac{100(0.05)+x(0.2)}{100+x} \\~\\ 0.12(100+x)\,=\,100(0.05)+x(0.2) \\~\\ 12+0.12x\,=\,5+0.2x \\~\\ 12-5=0.2x-0.12x \\~\\ 7\,=\,0.08x \\~\\ 87.5=x\)
the amount of 20% dye to add is 87.5 mL .
