Xiao Ming organized 17 students in this class to travel to the botanical garden during the summer vacation. The charging standard for the botanical garden ticket is: adult ticket: 8 yuan per ticket; child ticket: 5 yuan per ticket; group ticket: 20 people or more will get a 20% discount on the adult ticket price , please help Xiao Ming calculate how much they need at least to buy tickets.
小明组织本班17位同学利用暑假到植物园去旅游，植物园门票的收费标准是：成人票：8元1张；儿童票：5元1张；团体票：20人以上按成人票价打八折，请你帮助小明计算一下他们最少需要多少元买门票．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 * 20 * (4/5)</gadget>
<output>80</output>

<result>80</result>