The first term of the A.P. is \( a = 7 \), and the common difference is \( d = 6 \).
The general formula for the nth term of an A.P. is:
\[
T_n = a + (n - 1)d
\]
Step 1: We are given that the last term is 205, so:
\[
205 = 7 + (n - 1) \times 6
\]
Step 2: Simplify the equation:
\[
205 - 7 = (n - 1) \times 6
\]
\[
198 = (n - 1) \times 6
\]
\[
n - 1 = \frac{198}{6} = 33
\]
\[
n = 34
\]
Thus, the number of terms in the A.P. is 34.