There are three schools, A, B, and C. The number of people in school A (1/2) is equal to that of school B (1/3), and the number of people in school C is (3/7). It is known that school C has 120 more students than school A. Find How many people are there in the three schools?
有甲乙丙三个学校，甲校人数的(1/2)等于乙校人数的(1/3)，等于丙校人数的(3/7)，已知丙校比甲校多120人，求三校共有多少人？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) / (3/7)</gadget>
<output>7/6 = around 1.166667</output>

<gadget id="calculator">(7/6) - 1</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">120 / (1/6)</gadget>
<output>720</output>

<gadget id="calculator">720 + 120</gadget>
<output>840</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/2) / (1/3)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">720 * (3/2)</gadget>
<output>1_080</output>

<gadget id="calculator">720 + 840 + 1_080</gadget>
<output>2_640</output>

<result>2_640</result>