Answer
(a) A 7 lb cat should be given 1400 milligrams.
(b) An 8 oz kitten should be given 100 milligrams.
Work Step by Step
(a)
$\frac{1000\ mg}{5\ lb} = \frac{x\ mg}{7\ lb}$
$5x = 1000*7$
$\frac{5x}{5} = \frac{7000}{5}$
$x = 1400$ mg
(b)
$\frac{1000\ mg}{5\ lb} = \frac{x\ mg}{\frac{1}{2}\ lb}$
$5x = 1000*\frac{1}{2}$
$\frac{5x}{5} = \frac{500}{5}$
$x = 100$ mg