A zookeeper counted the heads of the animals in a zoo and found it to be 80. When he counted the legs of the animals he found it to be260. If the zoo had either pigeons or horses, how many horses were there in the zoo?

প্রশ্নঃ A zookeeper counted the heads of the animals in a zoo and found it to be 80. When he counted the legs of the animals he found it to be260. If the zoo had either pigeons or horses, how many horses were there in the zoo?