The farmer's uncle dug a canal, and 40% of the total length has been dug, and there are still 36 meters left. At this time, a young man passing by asked him: "If you dig another 35% of the total length, how many meters are left?
农民伯伯挖一条水渠，已经挖了全长的40%，还有36米．这时一位路过的年轻人问他："你再挖全长的35%，还剩多少米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">36 / (3/5)</gadget>
<output>60</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">60 * (7/20)</gadget>
<output>21</output>

<gadget id="calculator">36 - 21</gadget>
<output>15</output>

<result>15</result>