The number of chickens raised in the farm is 4 / 5 of that of ducks. The number of geese is 1 / 4 less than ducks. The number of chickens is 280 more than geese. How many chickens are raised in the farm

The number of chickens raised in the farm is 4 / 5 of that of ducks. The number of geese is 1 / 4 less than ducks. The number of chickens is 280 more than geese. How many chickens are raised in the farm

Suppose there are x ducks, 4 / 5x chickens and (x-1 / 4x) = 3 / 4x geese
Because there are 280 more chickens than geese,
So: 4 / 5x-280 = 3 / 4x
4/5x-3/4x=280
1/20x=280
x=280×20
x=5600
Then: 4 / 5x = 4480
A: the farm has 4480 chickens
Calculation error upstairs!