The number A is 180, which is 20 more than 40% of the number B, what is the number B?
甲数是180，比乙数的40%多20，则乙数是多少．
<gadget id="calculator">180 - 20</gadget>
<output>160</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">160 / (2/5)</gadget>
<output>400</output>

<result>400</result>