Aunt Li raises 1558 chickens, ducks and geese. The ratio of chickens to ducks is 6:7. There are as many geese as chickens. How many ducks does Aunt Li raise?

Aunt Li raises 1558 chickens, ducks and geese. The ratio of chickens to ducks is 6:7. There are as many geese as chickens. How many ducks does Aunt Li raise?

1558÷(6+6+7)x7
=1558÷19x7
=82x7
=574 (pieces)