Question 52509
{{{(12(0.12) + x(0.20))/(12 + x) = 0.14}}}
{{{1.44 + 0.2x = 0.14(12 + x)}}}
{{{1.44 + 0.2x = 1.68 + 0.14x}}}
{{{0.06x = 0.24}}}
{{{x = 4}}}
I hope that is right; my calculator is upstairs, and I am too lazy to go fetch it, so I did it in my head instead. I have full confidence in you checking it.
Good Luck,
N2^3