A bird flies between two trains

Two trains are 600 miles apart, traveling towards each other on the same tracks. One is going 65 mph, the other is going 55 mph. There is a bird that starts in the same direction as the 65 mph train, but is flying at 75 mph. It will continue flying until it reaches...

The Painted Cube

A cube measures at 6in x 6in x 6in. It is thinly cut into smaller cubes, each 1in x 1in x 1in that remain in the large cube shape. If I paint the outside of the large cube shape, how many smaller cubes have no paint on any of their sides?