There is some rice in the grain station, 20% of the total is sold on the first day, and 77 tons are sold on the second day. At this time, there is still (1/4) of the total amount left. How many tons of these rice were originally?
粮站有一些大米，第一天卖出总量的20%，第二天卖出77吨，这时还剩下总量的(1/4)，这些大米原有多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 - (1/4) - (1/5)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">77 / (11/20)</gadget>
<output>140</output>

<result>140</result>