## JohnnyCowCow 2 years ago Maria has two fair coins. She flips them in the air. She believes it is equally likely they land 2 heads, 2 tails, or 1 head and 1 tail. Which of the following statements is NOT true? Answers: A. The probability of 2 heads is 25 %. B. The probability of 1 head and 1 tail is 33 %. C. The probability of 2 heads is less than the probability of 1 head and 1 tail. D. The probability of either 2 heads or 2 tails is the same as the probability of 1 head and 1 tail.

1. mathstudent55

Maria has it wrong. Can you come up with all the possible outcomes of this coin toss?

2. JohnnyCowCow

... umm ok?

3. mathstudent55

Fill in this table: |dw:1364248207123:dw| Remember, each coin can only have an outcome of heads or tails.

4. JohnnyCowCow

5. mathstudent55

Right. How many possible different outcomes are there?

6. JohnnyCowCow

Four

7. JohnnyCowCow

It is either B or C I cannot decide

8. mathstudent55

Good. There are 4 possible outcomes. 1 outcome out of 4 is 2 heads (25% probability) 1 outcome out of 4 is 2 tails (25% probabilty) 2 outcomes out of 4 are 1 heads and 1 tails (50% probability)

9. JohnnyCowCow

So it is B?

10. mathstudent55

Correct. The probabillity of 1 heads and 1 tails is 50%, not 33%. That's why I wrote above Maria is wrong. She thought that all three outcomes have the same probabiltity.

11. JohnnyCowCow

Thank you! My teacher puts topics on our semester projects that she hasn't covered yet :P

12. mathstudent55

I guess she's challenging her students. Part of your challenge is to come to OS and ask to try to figure it out. You're welcome.