"ludicrous question" is correct and is often used in written English.
You might use it in a situation when you feel a question is absurd or ridiculous. For example, "What do you mean I have to wear a clown costume? That's a ludicrous question!".
It's a ludicrous question.
"In normal times, this would be a ludicrous question.
A week ago, or even three days ago, it would be a ludicrous question.
Russert's 18-minute filibuster on Reverend Wright -- pinning Obama down under ludicrous question after ludicrous question at a time when US and Iraqi deaths are mounting, Haitian children are dying of starvation in the streets, you can write in your own global crisis -- was as naked a display of corporate media's hideously-misplaced priorities as I have ever seen.
"That's my defense mechanism against pompous and ludicrous questions," Matthau explained.
I'd had enough of the ludicrous questions.
And, in addition to defending Dowty with his ludicrous "rhetorical question" defense, Chaplain Hernandez expressed his own opinion on the subject, with statements such as: "Leaders should be promoted because of sacrifice and integrity, not sexual immorality".
One of the participants in Mr. Apter's "Survivor" pool, Ben Decker, a 24-year-old management consultant from San Francisco, called the program "sort of ludicrous" and questioned whether it was going to work for CBS in the long run.
Whether he intends this to be quite so ludicrous is another question.
And at the heart of that rather ludicrous request is a question of power.
Simon doesn't question this ludicrous turn of events as none dare challenge the plotting of a Nobel prize-winning novelist who has twice won the Booker.
