a)
D30={1,2,3,4,5,6,10,15,30}
M10={0,10,20,30,40,50,60,70....} D30∩M10={10,30}
b)
D45={1,3,5,9,45}
M5={0,5,10,15,20,25,30,35,40,45,50....}
D45∩M5={5,45}
c)M25={0,25,50,75,100,125,150,175,200...}
D150={1,2,3,5,6,10,15,25,30,75, 150}
M25∩D150={25,50,75,15,}
d)
M12={0,12,24,36,48,60,72,84,96,108, 120,132...}
D120={1,2,3,4,5,6,8,10,12,15,20,24,30,40,60, 120}
M12∩D12={12,24,120}