A factory has 12 tons of coal and burned 1.5 tons in the first 3 days. According to this calculation, how many days will it take to burn the coal? (Solve with ratio)
某工厂有12吨煤，前3天烧了1.5吨，照这样计算，烧完这些煤共需多少天？(用比例解)
<gadget id="calculator">1.5 / 3</gadget>
<output>0.5</output>

<gadget id="calculator">12 / 0.5</gadget>
<output>24</output>

<result>24</result>