Dongdong did winter vacation homework, completed (1/6) of all the homework on the first day, (1/5) of the remaining homework on the second day, and (1/4) of the remaining homework on the third day, I finished (1/3) of the remaining homework on the fourth day, and half of the remaining homework on the fifth day. At this time, there are still 20 pages of homework left to be completed. How many pages are there in total for the winter vacation homework?
冬冬做寒假作业，第一天完成了全部作业的(1/6)，第二天完成了剩下作业的(1/5)，第三天完成了剩下作业的(1/4)，第四天完成了剩下作业的(1/3)，第五天完成了剩下作业的一半，此时还剩20页作业没有完成，那么寒假作业一共多少页？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">20 / (1/2)</gadget>
<output>40</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">40 / (2/3)</gadget>
<output>60</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">60 / (3/4)</gadget>
<output>80</output>

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

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 / (4/5)</gadget>
<output>100</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">100 / (5/6)</gadget>
<output>120</output>

<result>120</result>