No-brainer

[noh-brey-ner] /ˈnoʊˈbreɪ nər/

noun
1.
Informal. anything requiring little thought or effort; something easy or simple to understand or do.
/ˌnəʊˈbreɪnə/
noun
1.
(slang) something which requires little or no mental effort

Something that is absurdly simple or easy and requires little thought: “Making pumpkin pie can be a no-brainer if you use frozen pastry and canned filling.”

modifier

: Alden Essex is currently the undisputed king of no-brainer novels/ Lansing, with the help of no-brainer sequels such as Wayne’s World 2 and Addams Family Values, has the studio back on track

noun

Something very simple, requiring no intelligence: The question of which CAD program to buy is a nobrainer; Autodesk’s AutoCAD dominates the market/ Passing it seemed like a no-brainer, but it failed (mid1980s+)