"It's a no-brainer."
Meaning Something so simple to do or understand Something so obvious that you do not need to think much about it If you describe a question or decision as a no-brainer , you mean that it is a very easy one to answer or make and requires very little thought. [informal] If you describe a person or action as a no-brainer , you mean that they are stupid. [US, informal, disapproval] Note We need our brains to think and reason on things, that much is obvious. Some choices, however, are considered to be so easy to make, that a person does not even need to think about them much before making them. A choice like this is sometimes called a ‘no-brainer.’ Example: Mike was sweating bullets on a hot summer day and needed to cool off. His friend offered him a cold cup of lemonade, which Mike accepted without hesitation; it was a no-brainer for him. (In other words, he didn’t have to think about it too much; it was a simple decision for him to make.) More Example Sentences That last test que