You are having a discussion about sequences with your classmate. She insists that the sequence 2, 3, 5, 8, 12 must be either arithmetic or geometric. Is she correct or incorrect? Explain.

Question

texaschic101 · Answer

geometric  -- find the next number by multiplying
arithmetic -- find the next number by adding

do you see any kind of pattern ?

texaschic101 · Answer

remember, it has to be a common pattern...the same number between every number

texaschic101 · Answer

no...
this would be arithmetic : 2,4,6,8,10 -- common difference is 2 -- you have to add 2 to each number to get to the next number
geometric : 2,4,8,16 -- you have to multiply each number by 2 to get to the next number
does this make sense ?

anonymous · Answer

oh ok

texaschic101 · Answer

your sequence q=above has a pattern, but it is not a common pattern..
2,3,5,8,12......add 1 to get to next number, then add 2 to get to next number, then add 3 to get to next number....not the same number.
Therefore, it is not either arithmetic or geometric

texaschic101 · Answer

oops..typo...your sequence above

texaschic101 · Answer

there has to be a common difference or a common ratio....there is not