There are 1,000 parts in a batch, and 40 of them are unqualified after inspection. In order to make the pass rate reach 98% as soon as possible, at least how many qualified parts should be continuously produced.
一批零件有1000个，经检测有40个不合格，为了使合格率尽快达到98%，至少要再连续生产多少个合格零件．
<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<gadget id="calculator">1_000 * (49/50)</gadget>
<output>980</output>

<gadget id="calculator">1_000 - 40</gadget>
<output>960</output>

<gadget id="calculator">980 - 960</gadget>
<output>20</output>

<result>20</result>