The weight ratio of Li Dong, Wang Jun, and Zhang Xin is 3:4:5. Their average weight is 48 kg. What is Zhang Xin's weight in kg?
李东、王俊、张欣三人体重比是3：4：5，他们的平均体重是48千克，张欣的体重是多少千克．
<gadget id="calculator">3 + 4 + 5</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">48 * 3 * (5/12)</gadget>
<output>60</output>

<result>60</result>