A sequence will be arithmetic if there's a constant difference between terms.
The first sequence is not arithmetic, since the differences between the terms of the sequence are
[tex]4-3=1,6-4=2,10-6=4,18-10=8[/tex]
A sequence is geometric if there's a constant scaling factor being applied to each successive term. To determine if such a constant is there, take the ratio of successive terms.
The first sequence is also not geometric, because the ratios of consecutive terms are
[tex]\dfrac43,\dfrac64=\dfrac32,\dfrac{10}6=\dfrac53,\dfrac{18}{10}=\dfrac95[/tex]
So the first sequence would be assigned (N), which rules out options B and D. Do the same for the next two sequences, which are the only ones you'd need to check.
