Step 1
Given;
[tex]\begin{gathered} p=Pr\text{ success trial=}\frac{30}{100}=0.3 \\ q=Pr\text{ no success trial=1-q=1-0.3=0.7} \\ x=10 \end{gathered}[/tex]Step 2
State the expected value formula
[tex]Expected\text{ number=xq=0.7}\times10=7[/tex]Answer;
[tex]7[/tex]