Apulumber is fitting a water pipe that is 3-4 foot long on to a water pipe that is 2-12 foot long how long will the finished pipe be

First, find a common denominator.
12 will work.
3/4 becomes 9/12, because 4x3=12, and 3x3=9
2/12 stays the same, because the denominator is already 12.
Now, add the two together.
9/12+2/12=11/12
The finished pipe will be 11/12 ft. long. your welcome enjoy :D