It takes 15 days to transport a batch of chemical fertilizers by car A and 10 days by car B. Now after the total number (1/2) is transported by vehicle B alone, the rest is transported by two vehicles together. In this way, how many days does vehicle A have to transport this batch of fertilizers?
运一批化肥，甲车独运15天完成，乙车独运10天完成．现在乙车独运总数的(1/2)后，剩下的由甲乙两车合运，照这样，运完这批化肥时，甲车运了几天？
<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">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/15) + (1/10)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/2) / (1/6)</gadget>
<output>3</output>

<result>3</result>