[求助]一道prep的math题 大家帮我看看啊

Bobby bought two shares of stork, which he sold for $96 each. If he had a profit of 20% on the sale of  one of the shares but a lost of 20% percent on the sale of the other share, then on the sale of both shares combined Bobby had (a lost of 8$)

括号里面是答案，这道题太纠结了，怎么看怎么像是一道简单题，但是就是绕不过来这个弯，呵呵 见笑了  大家帮我看看吧