#### Answer

13$\frac{1}{8}$ qt

#### Work Step by Step

Given oil quantites are 4$\frac{1}{2}$ qt, 4$\frac{1}{4}$ qt and 4$\frac{3}{8}$ qt
Therefore total oil used = 4$\frac{1}{2}$ qt + 4$\frac{1}{4}$ qt + 4$\frac{3}{8}$ qt
=$\frac{9}{2}$ qt + $\frac{17}{4}$ qt + $\frac{35}{8}$ qt
=$ \frac{9}{2} \times$ $\frac{4}{4}$+ $ \frac{17}{4} \times$ $\frac{2}{2}$ + $\frac{35}{8}$ qt
=$\frac{36}{8}$ qt + $\frac{34}{8}$ qt + $\frac{35}{8}$ qt
=$\frac{105}{8}$ qt
=13$\frac{1}{8}$ qt