The ratio of males to females in the choir was 3:5. Later, 8 males were transferred. At this time, the ratio of males to females was 7:10. How many females were there in the choir?
合唱团里男、女生人数比是3：5，后来调来8名男生，这时男、女生人数比是7：10，合唱团原有女生多少人？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(7/10) - (3/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">8 / (1/10)</gadget>
<output>80</output>

<result>80</result>