Geometric progression with some given terms

Given
$a_4 = 6$

$a_{10} = 384$
 

Formula
$a_n = a_m r^{n - m}$
 

$a_{10} = a_4 r^{10 - 4}$

$384 = 6r^6$

$r^6 = 64$

$r = 2$   →   Common ratio           Answer for Part 1: [ D ]
 

$a_4 = a_1 r^{4 - 1}$

$6 = a_1 2^3$

$a_1 = 0.75$   →   First term           Answer for Part 2: [ A ]
 

$a_7 = a_4 r^{7 – 4}$

$a_7 = 6(2^3)$

$a_7 = 48$   →   Seventh term           Answer for Part 3: [ C ]