A pile of coal is planned to burn 0.8 tons per day and can be burned for 90 days. Due to improved technology, it now burns 0.6 tons per day. How many days can it be burned now? (answer with ratio)
一堆煤，计划每天烧0.8吨，可以烧90天，由于改进技术，现在每天烧0.6吨，现在可以烧多少天？(用比例解答)
<gadget id="calculator">0.8 * 90</gadget>
<output>72</output>

<gadget id="calculator">72 / 0.6</gadget>
<output>120</output>

<result>120</result>