certain factory used to burn 25 tons of coal per day. After 4 months of burning, it found that there was not enough coal in storage. In the next 5 months, it could only burn 18 tons of coal per day. How many tons of coal does the factory have? (according to 30 days per month)
某工厂原来每天烧25吨煤，烧了4个月后发现存煤不够了，接下来5个月每天只能烧18吨煤．该工厂原有煤多少吨？(每月按30天计)
<gadget id="calculator">25 * 30</gadget>
<output>750</output>

<gadget id="calculator">750 * 4</gadget>
<output>3_000</output>

<gadget id="calculator">18 * 30</gadget>
<output>540</output>

<gadget id="calculator">540 * 5</gadget>
<output>2_700</output>

<gadget id="calculator">3_000 + 2_700</gadget>
<output>5_700</output>

<result>5_700</result>