The sum of the three numbers A, B and C is 300, the number of A is 120, the number of C is the number of B (4/5), what is the number of C
甲、乙、丙三个数的和是300，甲数是120，丙数是乙数的(4/5)，丙数是多少
<gadget id="calculator">300 - 120</gadget>
<output>180</output>

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

<gadget id="calculator">1 + (4/5)</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">180 / (9/5)</gadget>
<output>100</output>

<gadget id="calculator">180 - 100</gadget>
<output>80</output>

<result>80</result>