When digging a canal, 20% of the total length was dug in the first week, and 37.5% of the total length was dug in the second week. At this time, it has exceeded the midpoint of 120 meters. How many meters is the total length of this canal?
挖一条水渠，第一周挖了全长的20%，第二周挖了全长的37.5%，这时已经超过中点120米，这条水渠全长多少米？
<gadget id="calculator">37.5 / 100</gadget>
<output>0.375</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/5) - (1/2)</gadget>
<output>-3/10 = around -0.3</output>

<gadget id="calculator">0.375 + (-3/10)</gadget>
<output>0.075</output>

<gadget id="calculator">120 / 0.075</gadget>
<output>1_600</output>

<result>1_600</result>