No real way of knowing for sure. I've seen them last for the reasonable lifespan of the vehicle, and I've seen them fail in a substantially shorter period of time. Lots of factors go into this, and there isn't a concrete answer to give here.
The radiators hoses lasts for about 100000 miles. It is however important to regularly check the radiator hose before these miles are reached.
The lower radiator hose is located at the bottom of the radiator.
In most cases the lower radiator hose feeds the water pump. The upper radiator hose feeds the radiator.
Follow the long large radiator hose to behind the valve cover. It is not the hose that goes from the top of the radiator to the front of the engine.
Look on top of the radiator and follow the hose from the radiator to the thermostat housing. Look on the bottom of the radiator and follow the hose up to bottom of the block.
a hose clamp
Look on top of the radiator and follow the hose from the radiator to the thermostat housing. Look on the bottom of the radiator and follow the hose up to bottom of the block.
drain the radiator down below the top hose and unhook the hose from the radiator and the engine and pull the hose off.
The lower radiator hose supplies the water pump. The upper radiator hose supplies the radiator.
Upper is hose connected to top of radiator, lower is hose connected to bottom of radiator.
Either the radiator hose is loose where it connects to the radiator or there is either a small hole in the radiator or in the radiator hose. Try checking the hose to see if it's loose or check for small holes in the hose or radiator.
Drain off the radiator coolant into a clean drain pan. Loosen radiator hose clamps. Remove radiator hose. Install in reverse order.