Fatty is climbing a mountain. The distance from the bottom of the mountain to the top of the mountain is 3 kilometers. He goes up the mountain at 1 kilometer per hour and goes down the mountain at 1.5 kilometers per hour. What is his average speed when going up and down the mountain?
小胖爬山，山底到山顶的距离是3千米，他上山每小时行1千米，下山每小时行1.5千米，他上、下山的平均速度是多少．
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

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

<gadget id="calculator">3 / 1.5</gadget>
<output>2</output>

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

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>