2Coins probability of Heads-tails in 40 tosses? HELP

[aisha]

2 coins are tossed at the same time There are 3 colums in a chart

1) Heads-Heads
2) Heads-Tails or Tails-Heads
3)Tails-Tails

the coins were tossed 40 times simultaneously.

What was the probability that heads-tails (or tails-heads) would appear? Show calculations.

(HINT: The probability of these two combinations must be added together because they were recorded together.)

Im thinking its 2/4 but not sure, and don't know what to show as calculations.
PLEASE HELP ME!

 

[TsunamiJoe]

(0_o) youve created 3 topics about this...you need to stop before you get banned, and to my observation this isn't the first time

but I am not so great with it either, but wouldn't it be 1/3 chance for all?

 

[aisha]

For your information all of my posts are different questions so mind your own business.

 

[BobG]

2 coins are tossed at the same time There are 3 colums in a chart

1) Heads-Heads
2) Heads-Tails or Tails-Heads
3)Tails-Tails

the coins were tossed 40 times simultaneously.

What was the probability that heads-tails (or tails-heads) would appear? Show calculations.

(HINT: The probability of these two combinations must be added together because they were recorded together.)

Im thinking its 2/4 but not sure, and don't know what to show as calculations.
PLEASE HELP ME!

Yes, you're correct.

You have a 50% chance of coin 1 coming up heads. If coin 1 comes up heads, you have a 50% chance of coin 2 coming up heads. .5 * .5 gives you a 25% chance of both coins coming up heads.

If you do the same for each combination, you wind up with a 25% chance of each combination coming up. Since the coins are tossed simultaneously, you don't know if you have heads-tails or tails-heads. So you add the probabilities for both combinations together.

 

[jtbell]

Since the coins are tossed simultaneously, you don't know if you have heads-tails or tails-heads. So you add the probabilities for both combinations together.

Unless, of course, you have two different coins (say a quarter and a loonie) and it matters which one is which. Then you would consider loonie-heads and quarter-tails as a different outcome from loonie-tails and quarter-heads, each with 25% probability.

 

[aisha]

can u show me what the calculation would look like BOB? I understand what your saying but not 100% sure.

 

[GCT]

If this pertains to statistics, you'll need to employ proper formulas and concepts to solve this equation, it may NOT be 1/2.

 

[aisha]

no this is not physics it was just a Bio lab using a little bit of probability to help understand mendel and the pea plant .