The number of girls in Dongfeng Middle School used to be 80% of the number of boys in the first year of junior high school. Later, 10 girls were transferred. Now the number of girls is five sixth of the number of boys. How many people were there before?
东风中学初一原来有女生人数是男生人数的80%，后来转来女生10人，现在女生人数是男生人数的六分之五，原来全部有多少人？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(5/6) - (4/5)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">10 / (1/30)</gadget>
<output>300</output>

<gadget id="calculator">300 * (4/5)</gadget>
<output>240</output>

<gadget id="calculator">240 + 300</gadget>
<output>540</output>

<result>540</result>