ANSWER
[tex]90\text{ baby snails}[/tex]EXPLANATION
Angela's snail has laid three clusters of eggs like the one in the picture.
The cluster in the picture contains 30 eggs. This implies that three clusters will contain three times that amount:
[tex]\begin{gathered} 3\cdot30 \\ \Rightarrow90 \end{gathered}[/tex]Hence, Angela should expect 90 baby snails.