Answer:
45 100
/ \ / \
3 × 15 2×50
3× 5 2×25
/ \
5×5
45 : 3×3×5
100: 2×2×5×5
common : 3×5
15
HCF: 15
x=2-y-z
x=5/2-y/2+z/2
x=-2+y-z
last one equally likely, the probability is 0.5
