Absent-minded Students

Two absent-minded students miss their math final examination. They agree that they will make up an excuse and stick with the same story. “Unfortunately, we had a flat tire on our way to school and couldn’t make it to the test on time,” they declared to their teacher. The teacher accepted their alibi, and asked them to take the final exam in separate rooms. The first question was 10 points that both students easily answered. The second question worth 90 points stated, “Which tire on the car was flat?”

What is the probability that both students came up with the same answer to the second question? Explain your solution.