The price of a certain vegetable in early June fell by 15% compared to early May, and rose by 20% in early July compared to early June. Did it rise or fall in early July compared to early May? What is the rate of change?
某种蔬菜六月初的价格比五月初跌了15%，七月初比六月初涨了20%，7月初比5月初涨了还是跌了？涨跌幅度是多少？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) / 1</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1 * (17/20) * (6/5)</gadget>
<output>51/50 = around 1.02</output>

<gadget id="calculator">(51/50) - 1</gadget>
<output>1/50 = around 0.02</output>

<result>1/50 = around 0.02</result>