$$a, 2a − 1, 3a − 2, 4a − 3, . . .$$c
For a particular number $$a$$, the first term in the sequence above is equal to $$a$$, and each term thereafter is $$7$$ greater than the previous term. What is the value of the 16th term in the sequence

Question

Uniteasy Admin · Accepted Answer

Since the second term is 7 greater than the first term, we have the following equation
$$(2a − 1) − a = 7$$c 
so that $$a = 8$$. 
The sequence is 8, 15, 22, . . . You can either continue to write out the sequence until the 16th term, or realize in a mathematical way.
Observe the sequence $$a, 2a − 1, 3a − 2, 4a − 3, . . .$$. The general term of the sequence can be represented by the following expression
$$a_n=na-(n-1)$$c
then the 16th term is
 $$16a − 15 = 16(8) − 15 = 128 − 15 = 113$$c
Therefore, D is correct

Multiple Choice Question (MCQ)

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