size-2 you're right ! i used size-1 on both i and j

I'm lose something, or this would check the same value many times?

"&&" is preferred over "and" as a logical operator in Ruby, "and" can lead to unexpected behavior in some cases.

Here's an answer I wrote up on Quora about it: Why don't many programmers use the keywords "or" and "and" in their programs but always opt for "||" and “&&"?.

Same fail to my solution

Me too

confused by this solution

Como exercício para o Ruby não exige conhecimentos específicos.