Road tyres on mountain bike I bought a Repco Warrior 29 mountain bike 3 months ago. The back tyre is now almost bald and needs to be replaced. Because of where I live there are no bike shops, so I can't buy tyres here and will have to order them from overseas.

My problem is that 3 months seems a short time to have to replace tyres (although it does see a lot of miles since I use it a lot). I don't ride offroad, and I'm wondering if that's part of the issue with the rapid wear.

Before I order any tyres, can anyone tell me through experience if it's a good idea (or even possible) to put road tyres on my mountain bike. Are there any pro's and cons to it? Should I replace both tyres or just the back one?

Update:- I now have my new tyres, ordered brake pads as well, and immediately noticed the smoother, easier, quieter ride on the way home (about an hour) Cheers all for the advice.
It's totally fine to use smooth tires on a mountain bike, if you use it as you describe. You will find it even more comfortable, just be a bit more cautious whenever it rains.

As @MikeBaranczak points, be careful with the size, 27, 29 are nowadays quite common. BUT ALSO have a look: 


how fat they are and if they fit with your actual wheel. 
valve type, again check it fits with your actual wheel.


Best and easiest way is to check what you have now and order the same size, valve and thickness but in flat.

About having to change them each 3 months, I would say is not normal (of course depends on km) but the first new-bike tires are usually a bit soft/not-good-quiality and they get flat very fast... maybe if you don't change them in 3 more months you have them already flat and you don't need to change them :)