to be too difficult for (a person) to do, understand etc

perplex

to confuse (a person)

confuse

to make (a person) feel uncertain, puzzled etc

bewilder someone

to take away (a person's) attention, concentration etc

divert attention; confuse

of mistake

mix up, misunderstand

a question or problem that is difficult to understand or answer; a game, toy etc designed to test a person's knowledge, skill or patience; to cause (a person) to become confused, worried (about the solution to a problem)

baffle, confuse