Answer:
300 chickens
Step-by-step explanation:
Let number of chickens = x
Let number of scheduled days that the farmers stock will last = y
Story 1
Number of chicken=x-15
Number of days =y+4
(x-15)(y+4)=0
4x-15y-60=0
Story 2
Number of chickens =x+20
Number of days =y-3
(x+20)(y-3)=0
-3x+20y-60=0
Form (1) and (2)
4x-15=-3x+20
7x=35y
X=5y
Sub x= 5y into (1)
20y-15y-300=0
5y=300=x