1. ## simple probability question

If I have two coins and I have the ability to land heads 60% of the time

What is the probability that I will land one heads and then one tails (40%)

probability of landing two heads would be 30% and two tails would be 20%, but what about one heads and one tails?

Thanks

2. Originally Posted by rish
If I have two coins and I have the ability to land heads 60% of the time

What is the probability that I will land one heads and then one tails (40%)

probability of landing two heads would be 30% and two tails would be 20%, but what about one heads and one tails?

Thanks
$0.6 \times 0.4 = 0.24 = 24\%$

It's the chance of getting heads multiplied by the chance of getting tails. It's clear if you draw a tree diagram

3. but if it were a 50/50 chance then wouldn't the probability be 50% of landing on of heads and one of tails?

4. Originally Posted by rish
If I have two coins and I have the ability to land heads 60% of the time
What is the probability that I will land one heads and then one tails (40%)
probability of landing two heads would be 30% and two tails would be 20%, but what about one heads and one tails?
Will you please explain the question?
What does "two coins and I have the ability to land heads 60% of the time" mean?

5. Originally Posted by rish
but if it were a 50/50 chance then wouldn't the probability be 50% of landing on of heads and one of tails?
If they're fair coins how does the following statement from the question come into it?

If I have two coins and I have the ability to land heads 60% of the time
If you have two fair coins there is a 50% chance of the first one landing heads and a 50% chance it is tails.

If it tails we ignore it but if it's heads we toss the second coin which is the same as the first so there is a 50% chance of getting tails.

Therefore we multiply the first 50% by the second 50% to get 25%.

I should note this is for heads then tails.

6. Ok, lets make things easier by excluding the fact that there are two coins, lets just make it one.

In one case the coin lands on heads 50% of the time
For heads to land twice the probability would be 25%
For tails to land twice it would also be 25%
But for one of each the probability would be 50%

Now lets change the situation to make heads land 60% of the time
probability of landing heads twice would be 30%
probability of landing tails twice would be 20%
Now, what is the probability of landing one heads and one tails?

7. Originally Posted by rish
Now lets change the situation to make heads land 60% of the time
probability of landing heads twice would be 30%
probability of landing tails twice would be 20%
Now, what is the probability of landing one heads and one tails?
NO, probability of landing heads twice would be $(.6)^2=.36$.

AND probability of landing tails twice would be $(.4)^2=.16$

8. oh ok, you have to square them.. so then how would i calculate the probability of landing one of each?

9. Originally Posted by rish
oh ok, you have to square them.. so then how would i calculate the probability of landing one of each?
Because the event can happen in two ways, HT or TH, it is
$(.6)(.4)+(.4)(.6)=2(.24)=.48$

BTW: NOTE $.36+.48+.16=1$