Question

How many terms are in the arithmetic sequence 1313, 1616, 1919, ……, 7070, 7373?

Answer 1

To find the number of terms in the arithmetic sequence, we need to use the formula 
$a_{n}= a_{1}+(n-1)d$    
where $a_{n}$ is the nth number, $a_{1}$ is the first number, n is the number of terms and d is the difference of the two consecutive numbers.
7373 = 1313 + (n - 1)(303)
7373 = 1313 + 303n - 303
7373 = 1010 + 303n
7373 - 1010 = 303n
6363 = 303n
6363 ÷ 303 = n
n = 21

Therefore, there are 21 terms in the arithmetic sequence given.