10 to 15 years if you take good care of it
A rabbit should be fed : Once a day with a bowl of rabbit food and have access to grass for a limited time . The rabbit should also get veg (carrot , dandelion etc ) about twice a week .
Actually, it's the opposite of the above answer. They should be provided with unlimited hay, absolutely no pellets, and a limited amount of fruits and veggies once to several times a week. My rabbit eats like crazy, so I refresh his plate of hay at least 4 times a day
That's true for adult rabbits!!
If your are feeding kits (baby rabbits) then you want to feed them several times but in small amounts. If you are feeding them formula (as in a case with orphaned kits) you would try and mimic the mother; feed them at night, not during the day.
But, if your bunnies are weaned then keep them supplied with hay and alfalfa, as well as some fruits and veggies.
Rabbits are clean animals and if they get a little dirty, they can usually be trusted to clean themselves. Of course, if they're dirty with a dangerous substance, like oil or chocolate sauce, you mustn't let them clean themselves because then they'll get sick; however, rabbit pee is okay for rabbits to consume in small amounts, so in that case it's okay to let them groom themselves. If, however, the rabbit isn't cleaning itself (perhaps it has mobility problems and isn't able to groom), or if the rabbit is dirty with a dangerous substance, you'll have to clean the rabbit yourself. Bathing rabbits is very risky business, so it shouldn't be undertaken unless absolutely necessary, and even then it must be done very, very carefully so that risks are minimized and the rabbit isn't hurt. See the related question below for details and helpful links.
Try giving clean timothy hay, bread crust, cheerios if he still won't eat he could be catching mucoid enteritis or something similar. Take to a vet to save rabbit.