Answer
4.40 dollarsgal
Explanation
In the original expression, we have the unit: rupees on the numerator, then in the conversion factor, we need rupees in the denominator so that this unit is canceled. Similarly, in the original expression, L is on the denominator, then in the conversion factor, we need L in th numerator to cancel it. That is,
![\begin{gathered} \frac{72.35\text{ rupees}}{1\text{ L}}*\frac{0.016\text{ dollars}}{1\text{ rupee}}*\frac{3.79\text{ L}}{1\text{ gal}}= \\ \text{ Canceling units and combining numerical values:} \\ =\frac{72.53*0.016\operatorname{*}3.79}{1\operatorname{*}1\operatorname{*}1}(dollars)/(gal)= \\ =4.40\text{ }(dollars)/(gal) \end{gathered}]()