A flower shop buys a batch of roses and sells 20% of them in the morning and 25% in the afternoon. If a total of 135 roses are sold in the morning and afternoon, how many roses are there in this batch?
鲜花店进一批玫瑰，上午卖出全部的20%，下午卖出全部的25%，如果上午和下午一共卖出135枝，这批玫瑰共有多少枝？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/5) + (1/4)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">135 / (9/20)</gadget>
<output>300</output>

<result>300</result>