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

  • Thread starter aisha
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  • #1
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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 dont know what to show as calculations.
PLEASE HELP ME! :redface:
 

Answers and Replies

  • #2
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offtopic said:
(0_o) youve created 3 topics about this...you need to stop before you get banned, and to my observation this isnt the first time

but im not so great with it either, but wouldnt it be 1/3 chance for all?
 
  • #3
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For your information all of my posts are different questions so mind your own business.
 
  • #4
BobG
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aisha said:
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 dont know what to show as calculations.
PLEASE HELP ME! :redface:
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.
 
  • #5
jtbell
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BobG said:
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.
 
  • #6
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can u show me what the calculation would look like BOB? I understand what your saying but not 100% sure.
 
  • #7
GCT
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If this pertains to statistics, you'll need to employ proper formulas and concepts to solve this equation, it may NOT be 1/2.
 
  • #8
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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 .
 

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