My triplets are 3 1/2, but I also have two sons who are 21 (married with a baby on the way) and one who is almost 13. Your best bet is to make a chart for the day, week or month, specifically listing what chore is for each child daily. We don't allow our kids to have any free time or play time (no videos, TV, etc) until homework and chores are done. You can put a star on their day when theirs are done or cross it out, whichever works best. Some do tickets for each chore or each day that is completed correctly. They can turn in their tickets for video/TV time. You can offer money for each day, 10-25 cents a day, so they buy something at the end of the week. There's many rewards you can do, but the best thing is to start with a chart and write down who does what and when. Rotate the chores or let them decide what chores they want to do. Sometimes kids prefer certain chores and they can choose on their own. Or put all the chores in a hat and let them draw them. However it works for you. At age 5, they may be able to help you come up with ideas, what will help motivate them to do what they need to do to make you, Dad and them all happy in the end. Good luck!
If you're interested in our online triplet parent group for more triplet support just go to http://groups.yahoo.com/group/Parents_Of_Triplets_Club
I live in New Cumberland if you'd ever like to chat.
K. B
mom to 5 including triplets
http://groups.yahoo.com/group/HarrisburgPAChat