An unprepared student makes random guesses on all questions of her multiple choice test. if there are 16 questions and each question has 4 possible answers, what is the probability she will answer at least one question correctly?

Multiple chouce questions generally all give a consistent 25% chance of getting the answer correct. The possibility of getting 1 out of 16 questions right is 6.25%. Multiply all probable outcomes.

25% * 6.25% = 1.5625%

Her chances of getting at least one answer correct is greater than or equal to 1.5625%.