Question

Trevor is holding 5 red balloons and 4 blue balloons. He randomly selects a balloon to give his sister, and then he randomly selects a balloon to give his brother. Are two events dependent or independent? Explain.

A) Dependent. The two siblings will want the same color balloon.
B) Independent. Girls always want red and boys always want blue.
C) Independent. There are a set number of red balloons and blue balloons.
D) Dependent. When the first balloon is taken, it affects the ratio of red to blue balloons.

Answer 1

Dependent. When the first balloon is taken, it affects the ratio of red to blue balloons.

Explanation:

Whatever color the sister choses is irrelevant, eliminating answers A and B, but it does change the odds. If there are 5 red balloons and 4 blue balloons, if the sister is given a blue balloon, the odds of the brother receiving a red balloon increases (vis versa).

Answer 2

d. because if you loseneither a red or blue balloon the number of balloons is lowered and the probability of either a red or blue balloon is decreased