Work Problem – Problem 1

$\text{1 hour and 40 minutes = 100 minutes}$ \[ \text{Rate} \times \text{Time} = 1 \] \[ (\frac{1}{100} + \frac{1}{x})(60) = 1 \] \[ x = 150min. (\frac{1hr.}{60min.}) \] \[ x = 2.5 hrs. \leftarrow \text{answer} \]