Strategies, Sample Questions, and Random Ramblings.
July 19, 2015
The way that GMAT sequences are written is what tends to make them most difficult for people. Once you get this part down, you will be in good shape. If we look at a basic sequence:
2, 4, 6, 8, 10, 12 .....
We could write this sequence like this:
Basically, the subscript is simply a term number and we could write the equation for this sequence as follows:
This is not terribly different from functions at this point; for whatever term number you are looking for you just plug that term number in for n to get your answer.
Another way you might see sequences written is like this:
This is not different from what we dealt with before, but the operation plays tricks on people’s minds. The simply means you are looking for the value of the term that has an index that is one before An - nothing more. Do not try to perform any mathematical operations with the n - 1, just think of it as a placeholder for a different value.
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