no-brainer 
noun informal
Something that requires or involves little or no mental effort: the enormous popularity of his TV show makes the book a no-brainer for him...
- The exams now consist disproportionately of no-brainers like: ‘When you were in school, were you a member of a sports team?’
- Counting these no-brainers as evidence of genius is absurd.
- This is a no-brainer, but one of the biggest mistakes hikers make is not realizing the total length of the hikes they are on.
- order arms
- order book
- order clerk
- order-disorder
- order-driven
- orderedness
- ordered pair
- order form
- Order in Council
- orderless
- orderliness
- orderly
- orderly book
- orderly corporal
- orderly officer
- orderly room
- orderly room clerk
- orderly sergeant
- order man
- order mark
- order number
- Order of Australia
- order of battle
- order of business
- Order of Canada