Chickens are 20 fewer than ducks, and ducks are more than chickens (1/5). How many chickens are there? what is the correct formula
鸡比鸭少20只，鸭比鸡多(1/5)．求鸡有多少只？正确的算式是多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 / (1/5)</gadget>
<output>100</output>

<result>100</result>