In the love activity of "Love Yushu", the amount of money donated by classmate A belongs to classmate B (5/21), and the amount of money donated by classmate C belongs to classmate A (4/5). 310 yuan, so how much does student B donate?
在开展"情系玉树"的爱心活动中，甲同学捐款的钱数是乙同学的(5/21)，丙同学捐款的钱数是甲同学的(4/5)，如果三名同学共捐款310元，那么乙同学捐款多少元？
<gadget id="calculator">5 / 21</gadget>
<output>5/21 = around 0.238095</output>

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

<gadget id="calculator">(4/5) * (5/21)</gadget>
<output>4/21 = around 0.190476</output>

<gadget id="calculator">1 + (5/21) + (4/21)</gadget>
<output>10/7 = around 1.428571</output>

<gadget id="calculator">310 / (10/7)</gadget>
<output>217</output>

<result>217</result>