There are 3 more boys than girls participating in the mathematics competition, and 20% fewer girls than boys. How many people participated in the competition? (answer in two ways)
参加数学竞赛的男生比女生多3人，女生比男生少20%，参加竞赛的共有多少人？(用两种方法解答)
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / (1/5)</gadget>
<output>15</output>

<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<gadget id="calculator">15 + 12</gadget>
<output>27</output>

<result>27</result>