Answer:
The answer to your question is 63 chromosomes, the mule is a hybrid.
Explanation:
The horse has 64 chromosomes and the donkey has 62 chromosomes, the mules is a hybrid cross of these 2 animals and has 63 chromosomes.
Mule is a cross of a male donkey and a female horse and due to is has an impar number of chromosomes it can not reproduce.