A worker processes a batch of parts. After improving the operation method, the processing time for the same number of parts is 40% of the original time. How much work efficiency has been improved?
一个工人加工一批零件，改进操作方法后，加工同样多的零件，用的时间是原来的40%，工作效率提高了多少
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / (2/5)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) - 1</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) / 1</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>