The original number of B team is A team (3/7). Now team A sends 30 people to team B, then team B belongs to team A (2/3). How many people were there in the two teams? (solution by equation)
乙队原有的人数是甲队的(3/7)．现在甲队派30人到乙队，则乙队是甲队的(2/3)．原来两队一共有多少人？(用方程解)
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * 30</gadget>
<output>20</output>

<gadget id="calculator">20 + 30</gadget>
<output>50</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(2/3) - (3/7)</gadget>
<output>5/21 = around 0.238095</output>

<gadget id="calculator">50 / (5/21)</gadget>
<output>210</output>

<gadget id="calculator">210 * (3/7)</gadget>
<output>90</output>

<gadget id="calculator">210 + 90</gadget>
<output>300</output>

<result>300</result>