It is Arithmetic. It follows a pattern of divide by 2, which gives it the name "Arithmetic" and you can think of it as "Arithmic," which sounds like rythm. It follows the rythm of Divide by 2. Hope this helps, and let me know if I made any mistakes!
Arithmetic is a sequence that you constantly add or subtract by only 1 number. For example: 30, 25, 20, 15, etc. You are constantly subtracting 5; or 15, 20, 25, 30, etc. You are constantly adding 5. So these sequences would arithmetic. Geometric is when you divide or multiply by only 1 number. For example: 5,,25, 125, 625, etc. You are constantly multiplying the numbers by 5; or 625, 125, 25, 5, etc. You are constantly dividing by the number 5. So, these would be geometric. 1.6, 0.8, 0.4, 0.2 would be a geometric sequence. Geometric is the correct answer, because you are constantly dividing by 2.
I did 6 problems for you. You can now do the other 4 problems and see how I did it. You need to have the same denominator and the add the fractions together.
