The weight ratio of copper to tin in a copper-tin alloy is 5:7, how many kilograms of tin is needed to make 360 kilograms of this alloy?
一种铜锡合金中铜与锡的重量比是5：7，要制成这种合金360千克，需要锡多少千克？
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">360 * (7/12)</gadget>
<output>210</output>

<result>210</result>