There are 250 books on the bookshelf in the upper row. If you move 30% of the books in the upper row to the lower row, then the number of books in the lower row is (8/7) times that of the remaining books in the upper row. How many books are there in the lower row? Book?
书架上排书，上排有250本，如果把上排书中的30%挪到下排，这时下排的书是上排书剩下的(8/7)倍，下排现有多少本书？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">8 / 7</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">250 * (7/10) * (8/7)</gadget>
<output>200</output>

<result>200</result>