The ratio of the number of boys to girls in a school's art team is 2:5. There are currently 6 boys. If the number of the art team increases to 49, how much will the number of girls increase according to the original ratio of boys and girls?
某校文艺队男、女生人数之比是2：5，现有男生6人，如果文艺队增加到49人，按原有的男、女生人数之比，女生增加多少人．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">49 * (5/7)</gadget>
<output>35</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">6 * (5/2)</gadget>
<output>15</output>

<gadget id="calculator">35 - 15</gadget>
<output>20</output>

<result>20</result>