Answer
$8.25$ days
Work Step by Step
We know that:
$\displaystyle Shelf\ life=\frac{k}{Temperature}$
We plug in the given values to find $k$:
$\displaystyle 33=\frac{k}{10}$
$k=330$
Thus:
$\displaystyle Shelf\ life=\frac{330}{Temperature}$
So we find the shelf life at a temperature of $40$ degrees:
$\displaystyle Shelf\ life=\frac{330}{40}=\frac{33}{4}=8.25$ days
