A restaurant bought 30 kilograms of salt and planned to use it for 60 days, but actually used 0.1 kilogram less than planned every day. How many days did the salt actually use?
某饭店买来30千克的盐，计划用60天，实际每天比计划少用0.1千克，这些盐实际用了多少天？
<gadget id="calculator">30 / 60</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) - 0.1</gadget>
<output>0.4</output>

<gadget id="calculator">30 / 0.4</gadget>
<output>75</output>

<result>75</result>