A factory used 35 tons of water in September, and saved (1/7) in October compared with September. How many tons of water was used in October?
某厂九月份用水35吨，十月份比九月份节约(1/7)，十月份用水多少吨？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">35 * (1/7)</gadget>
<output>5</output>

<gadget id="calculator">35 - 5</gadget>
<output>30</output>

<result>30</result>