Three flour mills can grind 33.6 tons of flour in 8 hours. Now the number of flour mills has increased to 12, and it takes 168 tons of flour. How many hours will it take?
3台磨面机8小时可磨面粉33.6吨，现在磨面机增加到12台，要磨面粉168吨，要多少小时．
<gadget id="calculator">33.6 / 8 / 3</gadget>
<output>1.4</output>

<gadget id="calculator">1.4 * 12</gadget>
<output>16.8</output>

<gadget id="calculator">168 / 16.8</gadget>
<output>10</output>

<result>10</result>