Final answer:
To determine the probability that a student guesses all three true-false questions incorrectly, calculate (1/2) ^ 3 resulting in 1/8, thus there is a 12.5% chance of all answers being non-correct.
Step-by-step explanation:
The subject of the question is Mathematics, and it pertains to probability theory at the High School level. The student is asked to calculate the probability of all three answers being incorrect when guessing on a three-question true-false exam. Since each question has two possible answers (true or false), and only one is correct, the probability of guessing incorrectly on one question is 1/2.
Therefore, the probability of guessing all three questions incorrectly is (1/2) × (1/2) × (1/2), which equals 1/8 or 0.125. So, there is a 12.5% chance that the student guesses all three questions incorrectly.