A class of 55 students went to visit the zoo. The price tag at the entrance said 5 yuan per person. More than 60 tickets are group tickets with a 15% discount. How to buy tickets for this class is more appropriate and how much money can be saved.
某班55名学生到动物园去参观，门口的价格牌上写着每人5元，60张以上为团体票，团体票八五折优惠，这个班怎样买票比较合适，可节省多少元．
<gadget id="calculator">55 * 5</gadget>
<output>275</output>

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

<gadget id="calculator">60 * 5 * (17/20)</gadget>
<output>255</output>

<gadget id="calculator">275 - 255</gadget>
<output>20</output>

<result>20</result>