Aplumber 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.