Question 1157357
{{{(0.20(20) + x)/(20 + x) = 0.25}}}
<pr>
{{{(4 + x)/(20 + x) = 0.25}}}
<pr>
4 + x = 0.25(20 + x)
<pr>
4 + x = 5 + 0.25x
<pr>
0.75x = 1
<pr>
x = 1.33 g