You toss n balls into n bins. for each toss there is a 1/n probability that the ball you toss lands in any one of the bins. after n tosses, what is the expected number of empty bins?

Three baby penguins and their father were sitting on an iceberg 0.50.50, point, 5 meters above the surface of the water. the father dove down 4.74.74, point, 7 meters from the iceberg into the water to catch dinner for his kids. what is the father penguin's position relative to the surface of the water?