For a kind of magazine, the wholesaler discounts 30% off the price and sells it to the book stalls, and the stall owner sells it to readers at a discount of 10%.
一种杂志，批发商按定价打七折批发给书摊，摊主将原定价格降低10%卖给读者，如果这种杂志每本卖6.3元，每卖出一本摊主从中赢利多少元．
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">6.3 / (9/10)</gadget>
<output>7</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">7 * (7/10)</gadget>
<output>49/10 = around 4.9</output>

<gadget id="calculator">6.3 - (49/10)</gadget>
<output>1.4</output>

<result>1.4</result>