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

In summary, the probability of coin 1 coming up heads is 2/4. The probability of coin 2 coming up heads is 1/3. The probability of both coins coming up heads is 1/4.
  • #1
aisha
584
0
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! :redface:
 
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  • #2
offtopic said:
(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?
 
  • #3
For your information all of my posts are different questions so mind your own business.
 
  • #4
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 don't 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
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
can u show me what the calculation would look like BOB? I understand what your saying but not 100% sure.
 
  • #7
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
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 .
 

1. What is the probability of getting exactly 20 heads in 40 coin tosses?

The probability of getting exactly 20 heads in 40 coin tosses is approximately 0.1765 or 17.65%.

2. What is the probability of getting more than 25 heads in 40 coin tosses?

The probability of getting more than 25 heads in 40 coin tosses is approximately 0.0011 or 0.11%.

3. Is the probability of getting heads or tails equal in 40 coin tosses?

Yes, the probability of getting heads or tails is equal in 40 coin tosses. Each toss has a 50% chance of landing on either heads or tails.

4. What is the expected number of heads in 40 coin tosses?

The expected number of heads in 40 coin tosses is 20. This is calculated by multiplying the number of tosses (40) by the probability of getting heads (0.5).

5. How does the probability of getting heads change if the coin is biased?

If the coin is biased towards heads or tails, the probability of getting heads in 40 tosses will also change. The exact change will depend on the degree of bias in the coin.

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