Lili uses red and yellow pigments to make orange. The mass ratio of red to yellow is 5:4. What is the mass of the red pigment in the total mass of the prepared product?
丽丽用红色和黄色两种颜料来配制橙色．红色与黄色的质量比是5：4．红色颜料的质量占配制好的总质量的多少．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>