There is a batch of rice in the grain store. On the first day, 12 bags of the total (1/2) of the total are sold, and the remaining (1/3) is sold on the second day. 1/4) there are 12 more bags, and on the fourth day, the remaining (1/5) and 12 more bags are sold on the third day, and then they are all sold out. How many bags are there in this batch of rice?
粮店有一批大米，第一天卖出总数的(1/2)多12袋，第二天卖出余下的(1/3)多12袋，第三天再卖出第二天余下的(1/4)又多12袋，第四天再卖出第三天余下的(1/5)又多12袋，这才全部卖完．这批大米共多少袋？
<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">12 / (4/5)</gadget>
<output>15</output>

<gadget id="calculator">15 + 12</gadget>
<output>27</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">27 / (3/4)</gadget>
<output>36</output>

<gadget id="calculator">36 + 12</gadget>
<output>48</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">48 / (2/3)</gadget>
<output>72</output>

<gadget id="calculator">72 + 12</gadget>
<output>84</output>

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

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">84 / (1/2)</gadget>
<output>168</output>

<result>168</result>