kind of schoolbag is sold at 10% off for 37.8 yuan, how much is the original price.
一种书包打九折出售37.8元，原价多少元．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">37.8 / (9/10)</gadget>
<output>42</output>

<result>42</result>