Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for $$\mathbf { a } _ { \mathbf { n } }$$ to find $$a _ { 20 }$$ , the 20th term of the sequence.
-The population of a town is increasing by 500 inhabitants each year. If its population at the beginning of 1990 was 27,033, what was its population at the beginning of 1995?
A) 29,533 inhabitants
B) 135,115 inhabitants
C) 29,033 inhabitants
D) 270,230 inhabitants

Question

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for $$\mathbf { a } _ { \mathbf { n } }$$ to find $$a _ { 20 }$$ , the 20th term of the sequence.
-The population of a town is increasing by 500 inhabitants each year. If its population at the beginning of 1990 was 27,033, what was its population at the beginning of 1995? 
A) 29,533 inhabitants
B) 135,115 inhabitants
C) 29,033 inhabitants
D) 270,230 inhabitants

Quizplus · Accepted Answer

The formula for the nth term of an arithmetic sequence is $$a_n = a_1 + (n - 1)d$$, where $a_1$ is the first term, $d$ is the common difference, and $n$ is the term number. Here, $a_1 = 27033$, $d = 500$, and for the population at the beginning of 1995, we calculate the 6th term (since 1990 is the first term, 1995 is the 6th year). Thus, $$a_6 = 27033 + (6 - 1) \times 500 = 27033 + 2500 = 29533$$.

Write a Formula for the General Term (The Nth Term) an\mathbf { a } _ { \mathbf { n } }an​

Write a Formula for the General Term (The Nth Term) $\mathbf { a } _ { \mathbf { n } }$