There are two unqualified parts in a batch, and the qualified rate is 98%, so how many qualified parts are there?
一批零件中有两个不合格，合格率是98%，那么有多少个合格零件．
<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<gadget id="calculator">1 - (49/50)</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">2 / (1/50)</gadget>
<output>100</output>

<gadget id="calculator">100 - 2</gadget>
<output>98</output>

<result>98</result>