Answer
2 weeks.
Work Step by Step
336 hr = wk
Use the unit fraction $\frac{1 day}{24 hours}$ to change hours to days and the unit fraction $\frac{1 week}{7 days}$ to change days to week. Notice how all the units divide out except week, which is the unit you want in the answer.
336 hr * $\frac{1 day}{24 hours}$ * $\frac{1 week}{7 days}$= 2 weeks.