In a mountain climbing competition, Xiaomei walked 40 meters per minute when going up the mountain, and reached the top of the mountain in 15 minutes. Then go down the mountain on the same road, walking 60 meters per minute. How many meters per minute does Xiaomei walk up and down the mountain on average?
在一次登山比赛中，小美上山时每分钟走40米，15分钟到达山顶．然后按原路下山，每分钟走60米．小美上、下山平均每分钟走多少米？
<gadget id="calculator">40 * 15 * 2</gadget>
<output>1_200</output>

<gadget id="calculator">15 / 60</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">40 * (1/4)</gadget>
<output>10</output>

<gadget id="calculator">10 + 15</gadget>
<output>25</output>

<gadget id="calculator">1_200 / 25</gadget>
<output>48</output>

<result>48</result>