Life expectancy of a cycle tube and tire? Can anyone please let me know the life expectancy (no of km or time period) of a cycle tube and tire?

Let us consider different cycles (MTB Hybrid Roadbike) and different terrain (off-road slightly rugged smooth) respectively. 

Though I have a hybrid and have rode around 1500 km on it without a change of the tubes, I would love to know the other cycle's life expectancy and it would be helpful for others too.
The tube will last the life of the tire, and more, if not punctured too much. 

The tire will last until it wears too thin and starts puncturing a lot, unless damaged. 

Tires do, however, become brittle and crack in the sidewalls from UV and ozone exposure, and will need to be replaced every 10 years or so if not worn out first. White wall and gum wall tires crack faster.  Tubes also will crack with age, around the valve stem.

Running too low of a pressure can also destroy a tire.

1500km is nothing, if the tires are kept properly inflated.