One dish requires 2 1/4 lb of shrimp
Second dish requires 7/8 lb of shrimp.
Total of shrimp:
[tex]\begin{gathered} 2\frac{1}{4}\text{ + }\frac{7}{8}\text{ =} \\ \\ \frac{9}{4}\text{ + }\frac{7}{8}=\text{ } \\ \\ \frac{18}{8}\text{ + }\frac{7}{8}\text{ = } \\ \\ \frac{25}{8}\text{ = 3}\frac{1}{8}\text{ Lb} \end{gathered}[/tex]