Using the interval notation how do I find the union and intersection of intervals?

Question

 How do I find the union and intersection of intervals using interval notation of A=yly <=2 ,B=yly >5 

Answer 1

Intersection

y ≤ 2 and y > 5

Do any numbers satisfy?

Union

y ≤ 2 or y > 5

(-oo, ] ∪ (5, oo)