There are three boxes: one contains apples, one contains oranges, and one contains both. The boxes are labeled incorrectly. If you can only open one box and take one fruit, which box should you open to correctly label all the boxes?
Five students, P, Q, R, S, and T, scored different marks in an exam: 85, 90, 75, 80, and 95. P scored more than Q but less than R. S scored 80. Who scored 90?