In the botanical garden, redwood trees account for 5% of the total number of trees, and ginkgo trees account for 7% of the total number of trees. There are 20 fewer redwood trees than ginkgo trees. How many trees are there in the botanical garden?
植物园中，红杉树占总棵数的5%，银杏树占总棵数的7%，红杉树比银杏树少20棵，植物园里共有多少棵树？
<gadget id="calculator">7 / 100</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(7/100) - (1/20)</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">20 / (1/50)</gadget>
<output>1_000</output>

<result>1_000</result>