The sum of the three numbers is 120, the number A is twice the number B, and the number C is 20 more than the number B, what is the number C?
三数之和是120，甲数是乙数的2倍，丙数比乙数多20，丙数是多少．
<gadget id="calculator">120 - 20</gadget>
<output>100</output>

<gadget id="calculator">2 + 1 + 1</gadget>
<output>4</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<result>25</result>