If the coefficients of three consecutive terms in the expansion of `(1+x)^n` are in the ratio 1:7:42, then find the value of `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 Coefficients**:
The coefficients of the \( (r+1)^{th} \), \( (r+2)^{th} \), and \( (r+3)^{th} \) terms in the expansion of \( (1 + x)^n \) are given by:
\[
C_{r+1} = \binom{n}{r}, \quad C_{r+2} = \binom{n}{r+1}, \quad C_{r+3} = \binom{n}{r+2}
...