How many terms of the A.P. ` 6`, `-(11)/2``,-5,dotdotdot`are needed to give the sum ` 25`?

Explanation

To solve the problem of how many terms of the arithmetic progression (A.P.) `6`, `-11/2`, `-5`, ..., are needed to give the sum `25`, we will follow these steps:

### Step 1: Identify the first term (A) and the common difference (D)
The first term \( A \) is given as \( 6 \).

To find the common difference \( D \), we can subtract the first term from the second term:
\[
D = -\frac{11}{2} - 6 = -\frac{11}{2} - \frac{12}{2} = -\frac{23}{2}
...