There is a pile of coal in the cafeteria. The mass ratio of the burned coal to the remaining coal is 3:5. It is known that 270 kilograms have been burned. How many kilograms are left? (Solve with ratio)
食堂有一堆煤，烧掉的和剩下的煤的质量比是3：5，已知烧掉270千克，还剩多少千克？(用比例解)
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">270 / (3/5)</gadget>
<output>450</output>

<result>450</result>