60 parts are processed per hour, the ratio of unprocessed parts to the total after 5 hours is 3:5, find the total.
每小时加工60个零件，5小时后未加工的零件与总数的比是3：5，求总数．
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">60 * (5/2) * 5</gadget>
<output>750</output>

<result>750</result>