To find the seventeenth term of the arithmetic progression (A.P.) given as 3, 8, 13, ..., we need to identify the initial term and the common difference of the sequence.
We use the formula for the \(n\)th term of an A.P., which is:
\(T_n = a + (n - 1) \cdot d\)
Here, we need to find the 17th term, so \(n = 17\). Plugging the values of \(a\), \(d\), and \(n\) into the formula, we get:
\(T_{17} = 3 + (17 - 1) \cdot 5\)
Calculating inside the parenthesis first:
\(T_{17} = 3 + 16 \cdot 5\)
\(T_{17} = 3 + 80\)
\(T_{17} = 83\)
Therefore, the seventeenth term of the A.P. is 83.
Thus, the correct option is 83.
Consider an A.P. $a_1,a_2,\ldots,a_n$; $a_1>0$. If $a_2-a_1=-\dfrac{3}{4}$, $a_n=\dfrac{1}{4}a_1$, and \[ \sum_{i=1}^{n} a_i=\frac{525}{2}, \] then $\sum_{i=1}^{17} a_i$ is equal to