To celebrate Children's Day, Xinhua Bookstore is offering 15% off children's books. Xiaoqiang's father gave him 50 yuan to buy books. If he buys two of the following books, how much money does Xiaoqiang have left? Please help Xiaoqiang to buy books: "Computer from Primary School": 15 yuan; "Children's Dinosaur World": 18.8 yuan; "Andersen's Fairy Tales" total 38 yuan.
新华书店为庆祝"六一"儿童节，儿童书籍一律八五折出售．小强的爸爸给他50元去买书，如果购下面书的其中两种，小强还剩多少元？请你为小强作购书参谋：《从小学电脑》：15元；《少儿恐龙大世界》：18.8元；《安徒生童话》上、下共38元．
<gadget id="calculator">18.8 + 38</gadget>
<output>56.8</output>

<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">56.8 * (17/20)</gadget>
<output>48.28</output>

<gadget id="calculator">50 - 48.28</gadget>
<output>1.72</output>

<result>1.72</result>