The gymnastics team has twice as many girls as boys. The average height of boys is 150 cm, and the average height of girls is 138 cm. Find the average height of all the students in the gymnastics team. (Hint: Suppose there are 10 boys and 20 girls.)
体操队女生人数是男生的2倍．男生平均身高150厘米，女生平均身高138厘米．求体操队全体同学的平均身高．(提示：假如男生10人，女生20人．)
<gadget id="calculator">10 * 150</gadget>
<output>1_500</output>

<gadget id="calculator">20 * 138</gadget>
<output>2_760</output>

<gadget id="calculator">1_500 + 2_760</gadget>
<output>4_260</output>

<gadget id="calculator">10 + 20</gadget>
<output>30</output>

<gadget id="calculator">4_260 / 30</gadget>
<output>142</output>

<result>142</result>