Ron, Sue, and Ted arrive at the beginning of a professor’s office hours. The amount of time they will stay is exponentially distributed with means 1, 1/2, and 1/3 hours. (a) What is the expected time until only one student remains? (b) For each student, find the probability they are the last student left. (c) What is the expected time until all three students are gone?

Abilliard ball is struck by a cue. it travels 1 0 0 cm 100cm before ricocheting off a rail and traveling another 1 2 0 cm 120cm into a corner pocket. the angle between the path as the ball approaches the rail and the path after it strikes the rail is 4 5 ∘ 45 ∘ . how far is the corner pocket from where the cue initially struck the ball? do not round during your calculations. round your final answer to the nearest centimeter.