perplexed

"She had a perplexed look on her face after hearing the complicated explanation."

"The students were perplexed by the difficult math problem."

"I felt perplexed when I couldn't figure out the puzzle."

"The unexpected turn of events perplexed everyone in the meeting."

"Her strange behavior continues to perplex her friends."

"The riddle perplexes anyone who attempts to solve it."