#### Answer

$16$-pound force

#### Work Step by Step

Let $F$ be the force of the wind.
Let $A$ be the surface area.
Let $s$ be the speed of wind.
$F=kAs$
$F=20; A=12; s=10$
$20 =k(12)(10)$
$k=\frac{1}{6}$
$F=\frac{1}{6}As$
$A=8; s=12$
$F=\frac{1}{6}(8)(12)$
$F=16$-pound force