Answer:
1. 5, 10, 15, 20, = C. Arithmetic, common difference is 5
2. 128, 32, 8, 2, = Geometric , Common ratio is 0.25
3. 20, 17, 14, 11, = Arithmetic , Common difference is -3
4. 1, 3, 9, 27, = Geometric , common ratio is 3
Step-by-step explanation:
In arithmetic sequence we calculate the common difference and it is gotten by:
[tex]T_2-T_1 \: or \\ T_4-T_3[/tex]
In geometric progression we calculate common ratio and it is gotten by :
[tex] \frac{T_2}{T_1} \: or \: \\ \frac{T_4}{T_3} [/tex]