The sum of the three numbers A, B, and C is 300, the number of A is 120, the ratio of B and C is 5:4, what is the number of C?
甲、乙、丙三个数的和是300，甲数是120，乙、丙的比是5：4，丙数是多少．
<gadget id="calculator">300 - 120</gadget>
<output>180</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">180 * (4/9)</gadget>
<output>80</output>

<result>80</result>