The fourth, seventh, and the last term of a G.P. are 10, 80, and 2560, respectively. Find the first term and the number of terms in G.P.

Explanation

To solve the problem, we need to find the first term (A) and the number of terms (n) in the given geometric progression (G.P.) where the fourth term (A4) is 10, the seventh term (A7) is 80, and the last term (AN) is 2560.

### Step-by-step Solution:

1. **Identify the General Formula for G.P.:**
The n-th term of a G.P. can be expressed as:
\[
A_n = A \cdot R^{n-1}
...