There are 15 girls in a class and 20% more boys than girls. How many boys are there?
某班有女生15人，男生比女生多20%，男生有多少人．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">15 * (6/5)</gadget>
<output>18</output>

<result>18</result>