The probability (P) of event A occurring is:
[tex]P(A)=\frac{\text{ number of favorable outcomes to A}}{\text{ total number of outcomes}}[/tex]The probability of 2 consecutive events A and B occur is:
[tex]P=P(A)*P(B)[/tex]Then, let's calculate the probability of selecting an insect:
Favorable outcomes: 10
Total outcomes: 30
[tex]P(insect)=\frac{10}{30}=\frac{1}{3}[/tex]Now, let's calculate the probability of selecting tree:
If the insect card is replaced:
Favorable outcomes: 8
Total outcomes: 30
[tex]P(B)=\frac{8}{30}=\frac{4}{15}[/tex]If the insect card is not replaced:
Favorable outcomes: 8
Total outcomes: 29
[tex]P(B)=\frac{8}{29}[/tex]The probability of randomly selecting an insect and then a tree is:
With replacement:
[tex]\begin{gathered} P=\frac{1}{3}*\frac{4}{15} \\ P=\frac{4}{45} \end{gathered}[/tex]Without replacement:
[tex]\begin{gathered} P=\frac{1}{3}*\frac{8}{29} \\ P=\frac{8}{87} \end{gathered}[/tex]Answer:
With replacement: 4/45
Without replacement: 8/87