#### Answer

6 weeks

#### Work Step by Step

Substitute the given weight and solve for t.
$W=3t^2$
Substitute the weight for W.
$108=3t^2$
Divide both sides by 3.
$108 \div3=3t^2\div3$
Simplify.
$36=t^2$
Take the square root of each side.
$\sqrt{36}=\sqrt{t^2}$
Simplify.
$6=t$