A cowboy arrives in town on Friday. He stays for 3 days and then leaves on Friday. How is that possible?
You will get the answer in the riddle itself, if you read the riddle carefully.
The riddle says “A cowboy arrives in town on Friday.” So Friday is the name of the horse on which he comes. Hence, the only possibility is he arrives on the horse friday on Tuesday, stays for 3 days and leaves on the same horse on Friday.
A cowboy arrives on sunday