Answer
a) $\{7.5, 1.875, 0.46875, 0.1171875\}$
b) $h_n = 0.25^n(30)$
Work Step by Step
a) $h_n = rh_{n-1}$
$h_1 = 0.25h_0 = 7.5$
$h_2 = 0.25h_1 = 1.875$
$h_3 = 0.25h_2 = 0.46875$
$h_4 = 0.25h_3 = 0.1171875$
b) We have to multiply the initial value $h_0$ by $r$, $n$ number of times.
$h_n = r^nh_{0} = 0.25^n(30)$