"Foolish questions" refers to questions that lack intelligence or common sense. These questions seem silly or pointless, often because they show a lack of understanding or knowledge about a particular topic. Full definition
These sailors are comparable to Jesus» disciples, who disbelieve Jesus, ask foolish questions, and show general ignorance about everything. (religion.blogs.cnn.com)
Getting involved with foolish questions: 2 tim 2:23; t - itus 3:9 205. (religion.blogs.cnn.com)
The only foolish question is the one you don't ask, because you don't get the answer to that one... (wattsupwiththat.com)