Let the first three terms \( 2 \), \( p \) and \( q \), with \( q \neq 2 \), of a G.P. be respectively the \( 7^{\text{th}} \), \( 8^{\text{th}} \) and \( 13^{\text{th}} \) terms of an A.P. If the \( 5^{\text{th}} \) term of the G.P. is the \( n^{\text{th}} \) term of the A.P., then \( n \) is equal to:
