The coordination number for the AI3+ ion is typically between four and six. Use the anion coordination

Question:

The coordination number for the AI3+ ion is typically between four and six. Use the anion coordination number to determine the coordination number in the following compounds:
(a) AlF3 where the fluoride ions are two coordinate,
(b) Al2O3 where the oxygen ions are six coordinate,
(c) AlN where then it ride ions are four coordinate?