A rat can finish a maze in about 3 minutes. If a small backpack is put on the rat so it reduces its speed by 50%, how much longer will it take the rat to finish the maze?

When the rat's speed is reduced by 50%, it means the rat will take twice as long to cover the same distance. Therefore, the rat would take 2 times 3 minutes, or 6 minutes, to finish the maze with the backpack.
So, with the small backpack slowing down the rat, it will take the rat an additional 3 minutes (6 minutes - 3 minutes) to finish the maze compared to when it didn't have the backpack.