Master Yang produced 225 parts in 3 hours. After the technological innovation, he produced 180 parts in 2 hours. How much did the production efficiency increase?
杨师傅3小时生产零件225个，技术革新后，2小时生产180个，生产效率提高了百分之几？
<gadget id="calculator">180 / 2</gadget>
<output>90</output>

<gadget id="calculator">225 / 3</gadget>
<output>75</output>

<gadget id="calculator">90 - 75</gadget>
<output>15</output>

<gadget id="calculator">15 / 75</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>