The first term of an AP is 5, the last term is 45 and the sum is 400. Find the number of terms and the common difference.

Explanation

To solve the problem step by step, we will use the formulas for the nth term and the sum of the first n terms of an arithmetic progression (AP).

### Step 1: Identify the given values
- First term (a) = 5
- Last term (l) = 45
- Sum of the first n terms (S_n) = 400

### Step 2: Use the formula for the sum of the first n terms
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