It takes 1.8 minutes for Xiaohua to go from the first floor to the third floor. How many minutes does it take to go from the first floor to the seventh floor at the same speed?
小华从一楼上到三楼用1.8分钟，同样的速度从一楼上到7楼要多少分钟．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">1.8 / 2</gadget>
<output>0.9</output>

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

<gadget id="calculator">0.9 * 6</gadget>
<output>5.4</output>

<result>5.4</result>