SAT: Sequences and sets Quiz

The sequences you'll see on the SAT are usually arithmetic or geometric. Arithmetic sequences progress through adding a common difference to the previous term. This could be a positive or negative number. Geometric sequences progress through multiplying the previous term by a common ratio, which could be a fraction or integer.
You should also understand that the union of two or more sets consists of all of the terms in the sets, while the intersection of those sets consists of the terms they have in common.