After inspection of a batch of parts, it is found that there are 4 unqualified parts, and the qualified rate is 98%, so how many qualified parts are there?
一批零件经检验，发现有4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">4 / (1/50)</gadget>
<output>200</output>

<gadget id="calculator">200 - 4</gadget>
<output>196</output>

<result>196</result>