Let...
x-represent (20%) of the number of goat
y-represent (20%) of the number of cows
Equations:
5x+5y=40
x+2y=11
Solve by elimination.
5x+5y=40
-(5x+10y=55)
---------------------
-5y=-15
y=3
x+2(3)=11
x=5
The ratio of goats left to cows left is 20% goats:40 % cows.
That will be 5:3(2) = 5:6 (already in reduced form).
answer: 5:6