Question

help ex 17!!!!!!!!!!!!!!!!!!!!

Answer 1

3 ≤ x ≤ 30  ⇔ x ∈ {3,4,5.....30}
A = {3,4,6,12}
B = {5,10,15,20,25,30}
C = {3,6,12,15,21,24,30}
D = {6,10,14,18,22,26,30}
E = Ф
F = {6,12,18,24,30}