It took Ding Ding 2 minutes to go from the 1st floor to the 3rd floor, and how many minutes did it take to go from the 1st floor to the 7th floor at the same speed?
丁丁从1楼上到3楼用了2分钟，以同样的速度从1楼上到7楼用多少分．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

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

<result>6</result>