'It's a no-brainer'.

[sandyRoe]

What does this phrase mean? Something so simple that it needs no brains to complete it, or what?

[craft1948]

Yes

[China Doll]

I take it to mean that something requires no thought to make a decision or give an answer.

Like 'Would China Doll like a bacon roll?'

[craft1948]

There's an eclair shouting my name from the fridge...............

[China Doll]

The answer to that would involve several swearies.

[jno]

http://www.phrases.or...nings/no-brainer.html

tracing it to a comic strip in 1959

[mccfluff]

would you like another?

[China Doll]

I would like some wine.

[boxtops]

It took me a very long time to realise that it means the opposite of "if you do that thing, you have no brains" - I don't like the expression at all.