It took Uncle Li 30 seconds to climb from the first floor to the third floor. According to this calculation, how many seconds will it take him to climb from the third floor to the seventh floor?
李叔叔从一楼爬到三楼用了30秒钟，照这样计算，他从三楼爬到七楼要用多少秒？
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<result>60</result>