Union and Intersections of a set

Question

How do I find the union and intersection for the following sets

 

F=w|w≤3

H=w|w >8

 

the first one I came up with no solution

Answer 1

F = {w l w ≤ 3}      H = {w l w > 8}

 

F U H = union of F and H 

 

          = all numbers that are in F, in H, or in both F and H

 

          = {w l w ≤ 3 or w > 8}  

 

F ∩ H = intersection of F and H

 

          = all numbers that are in both F and H

 

          = {  }