A project A and B cooperate to complete (7/10) of the whole project, and the rest is completed by A alone. A has done 10 days in total. This project will be done by A alone in 15 days. If B does it alone, How many days?
一项工程甲、乙合作完成了全工程的(7/10)，剩下的由甲单独完成，甲一共做了10天，这项工程由甲单独做需15天，如果由乙单独做，需多少天？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) / (1/15)</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">10 - (9/2)</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">(1/15) * (11/2)</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">(7/10) - (11/30)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) / (11/2)</gadget>
<output>2/33 = around 0.060606</output>

<gadget id="calculator">1 / (2/33)</gadget>
<output>33/2 = around 16.5</output>

<result>33/2 = around 16.5</result>