Answer:
1. 3, 12, 48, 192, 768 Ratio: x4
2. 8, 16, 32, 64, 128 Ratio: x2
3. 120, 60, 30, 15, 7.5 Ratio: ÷2
4. 5, 10, 20, 40, 80, 160 Ratio: x2
5. 1.3?, 4, 12, 36, 108, 324 Ratio: x3
Hope this helps!
I'm not sure about the first one on question 5 though.
