Answer:
Explanation:
Assume that after each shaking, a silver dollar has an equal chance of "head" or "tail" up.
There will be likely 100/2 = 50 dollar coins with "heads" up. Removing them leaves 50 coins.
Again after the second shakes, 50/2 = 25 coins will likely be "heads" up. Removing them leaves 25 coins.
After the third shakes, approximately 25/2 = 12.5 coins will be "heads" up. Of course there is no 0.5 coin. Rounding up you likely get to keep 13 dollar coins.
Answer:
Physical characteristics.
Explanation:
She knew what type of birds they were based on their physical characteristics.
She didn't see their nests, or see them eat, and she didn't test and analyze their genetics, so a is the correct option.