Dad goes upstairs twice as fast as Xiaofang. It takes 8 minutes for Xiaofang to go from the first floor to the fifth floor. How many minutes does it take for Dad to go from the first floor to the seventh floor?
爸爸上楼的速度是小芳的2倍，小芳从一楼到五楼要8分钟，爸爸从一楼到七楼要多少分钟？
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">8 / 4</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>