Question

Dados os intervalos A = [1, 5] e B = [2, 7], o intervalo A ∪ B é:
  [1, 7]

  [1, 4]

  [1, 2]

  [2, 5]

  [5, 7]

Answer 1

Veja os intervalos:

0      1        2         3          4           5          6           7

------++++++++++++++++++++++++----------------------------  A
--------------+++++++++++++++++++++++++++++++---------- B
------++++++++++++++++++++++++++++++++++++---------- A ∪ B

A ∪ B = [1, 7]