A farm raises 140 geese. The number of geese is equal to that of ducks (7/10), and the number of ducks is equal to that of chickens (4/7). How many chickens are there?
某饲养场养鹅140只，鹅的只数是鸭的(7/10)，鸭的只数是鸡的(4/7)，养鸡多少只？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">140 / (7/10) / (4/7)</gadget>
<output>350</output>

<result>350</result>