There are 62 large and small boxes, 5 small boxes per ton, and 3 large boxes per ton. The boxes are now to be removed by a truck. If the big box is loaded first, 15 small boxes can be packed after the big box is filled. If the small boxes are loaded first, 15 large boxes can be packed after the small boxes are filled. So among these boxes, how many big boxes are there?
大小箱子共62个，小箱子5个一吨，大箱子3个一吨．现要用一辆卡车运走这些箱子．如果先装大箱子，大箱子装完后恰好还可以装15个小箱子．如果先装小箱子，小箱子装完后恰好还可装15个大箱子．那么这些箱子中，大箱子有多少个．
<gadget id="calculator">62 / 5</gadget>
<output>62/5 = around 12.4</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">15 / 5</gadget>
<output>3</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">(62/5) + 2</gadget>
<output>72/5 = around 14.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/3) + (1/5)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(72/5) / (8/15)</gadget>
<output>27</output>

<result>27</result>