A supermarket has 3 checkout lanes, and the settlement can be completed in 25 minutes, and 6 checkout lanes, and the settlement can be completed in 15 minutes. Now it takes 5 minutes to complete the settlement, how many checkout lanes does the supermarket need to open?
某超市开3个结账通道，25分钟可结算完，开6个结账通道，15分钟可结算完，现在要5分钟结算完，超市需开多少个结账通道．
<gadget id="calculator">3 * 25</gadget>
<output>75</output>

<gadget id="calculator">6 * 15</gadget>
<output>90</output>

<gadget id="calculator">90 - 75</gadget>
<output>15</output>

<gadget id="calculator">25 - 15</gadget>
<output>10</output>

<gadget id="calculator">15 / 10</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * 25</gadget>
<output>75/2 = around 37.5</output>

<gadget id="calculator">75 - (75/2)</gadget>
<output>75/2 = around 37.5</output>

<gadget id="calculator">(75/2) / 5</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">(15/2) + (3/2)</gadget>
<output>9</output>

<result>9</result>