We have to trade 5 bunnies for a donkey.
Solution:
To calculate how many bunnies could be exchanged for a donkey, we have to multiply the exchange rates of each animal/bird.
One bunny = 3/4 chickens (0.75 chicken),
One chicken = 2/5 pigs (0.4 pigs)
One pig = 2/3 donkeys (0.67 donkeys).
On multiplying all of the above rates we get,
0.75*0.4*0.67=0.2
Since we now know a bunnies worth is 0.2 donkey
Therefore, (1/0.2=5) 5 bunnies to trade for a donkey.