put the on the same denominatior.
So it's 26 4/12 and 10 3/12.
Substract 10 3/12 from 26 4/12 (4/12 - 3/12 = 1/12)
You'll have 16 1/12 now divide it by 2 (because it's the total measurement that's free on the door (sorry if it's not clear...)).
Note: 2 is in reality 2/1
When you divide a fraction, you multiplie by the inverse.
So you keep the 1/12 and you multiply it by the invers of 2/1...1/2
1/12 * 1/2 = 1/24
Now add the 16 divide by 2 and you'll have you have your answer.
8 1/24
