The number B is 120, and the number B is 20% greater than the number A. What is the number A?
乙数是120，乙数比甲数大20%，甲数是多少？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">120 / (6/5)</gadget>
<output>100</output>

<result>100</result>