The coefficients of three consecutive terms in the expansion of `(1+x)^n` are in the ratio 1:7:42. `\ ` Find `ndot`

Explanation

To solve the problem, we need to find the value of \( n \) given that the coefficients of three consecutive terms in the expansion of \( (1+x)^n \) are in the ratio \( 1:7:42 \).

### Step-by-Step Solution:

1. **Identify the Terms**:
The three consecutive terms can be denoted as:
- \( T_{r-1} \) (the \((r-1)\)-th term)
- \( T_r \) (the \(r\)-th term)
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