Master Li used to take 5 minutes to process a part, but now he can finish it in 2 minutes. How much has his productivity improved
李师傅原来加工一个零件要5分钟，现在2分钟就可以完成．他的工作效率提高了多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/2) - (1/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) / (1/5)</gadget>
<output>3/2 = around 1.5</output>

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