h help please I need answers now thank you

Answer:
A.
15: 3 and 5
25: 5
Common factor/s: 5
B.
6: 6, 12, 18, 24, 30, 36
9: 9, 18, 27, 36, 45, 54
18: 18, 36, 54, 72, 90
Common multiples: 18 and 36