There are two trucks, big and small. The load of the big truck is 15 tons, and the load of the small truck is 2/5 of that of the big truck. The big truck has finished delivering the goods 6 times. How many times does the small truck need to deliver the goods?
有大、小两辆卡车，大卡车的载重量是15吨，小卡车的载重量是大卡车的(2/5)，大卡车6次运完货物，小卡车需要多少次才能运完？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">15 * (2/5)</gadget>
<output>6</output>

<gadget id="calculator">6 / 6</gadget>
<output>1</output>

<gadget id="calculator">15 * 1</gadget>
<output>15</output>

<result>15</result>