Well, you have to be given an interval. That is not an interval.
You should be given something like

If you add those fractions up you'll just get a point on the number line.
Find the LCD for all of them which is 9/6 - 4/6 + 3/6 = 8/6 = 2/3
You'll end up with a point on 2/3
Answer:
See below
Step-by-step explanation:
To begin, it is volume, not area
1. 8 x 12 x 17 = 1632 in ^3
5. 9 x 9 x 13.5 = 1093.5 in^3
If you want to find SURFACE AREA:
1. 2(8 x 12) + 2(8 x 17) + 2(17 x 12) = 872 in^2
5. 2(9 x 9) + 4(9 x 17) = 774 in^2
The answer is 17
4x3=12
3x2=6
12+6=18
18-1=17