A car transported a pile of yellow sand. It was planned to transport 15 tons per day, and the task could be completed within the scheduled time. The actual transport of 20 tons per day was completed 3 days ahead of schedule. How many tons of this batch of yellow sand were there?
一辆汽车运一堆黄沙，计划每天运15吨，可以在预定时间内完成任务，实际每天运20吨，结果提前3天运完，这批黄沙有多少吨？
<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<gadget id="calculator">20 - 15</gadget>
<output>5</output>

<gadget id="calculator">60 / 5</gadget>
<output>12</output>

<gadget id="calculator">12 * 15</gadget>
<output>180</output>

<result>180</result>