Answer:
16: 0.5, 5, 7.5
17: 62, 434, 682
18: 12.3, 62.5, 10
19: 1, 75, 300
Explanation:
16: 9/18=0.5 so halve the numbers
17: 186/3=62 so multiply numbers by 62
18: 24.6/2= 12.3 so multiply by 12.3 and divide for the last one
19: 125/5=25 so for the first one divide by 25 and for the last two times by 25