Question 622213
<pre>
Suppose he paid x cents for each egg. So his total cost was 100x cents.

He sold 80 at x+30%x cents each or 1x+.30x or 1.30x, so he took in 80(1.30x)
or 104x cents for those 80 eggs.

He sold 20 at x-40%x each or 1x-.40x or 0.60x, so he took in 20(0.60x)
or 12x cents for those 20 eggs.

So he took in a total of 104x+12x or 116x, so his profit was 116x-100x
cents or 16x cents.

16x cents is {{{16x/(100x)}}} or 16% of the 100x cents he paid for the 100
eggs.

Answer: 16% gain.

Edwin</pre>