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AR15.COM
11/17/2015 11:20:39 AM EDT
Wife was taking a online college entrance test and asked me to look at this question.

As I see it the correct answer is 1/144 but I know they are wanting to see 1/24

Am I correct or am I over thinking it.
(1/2×1/6)×(1/2×1/6) vs. 1/2 × 1/2×1/6









11/17/2015 11:25:21 AM EDT
[#1]
I believe it is the second answer you posted. You should only count the dice once.  (1/2)*(1/2)*(1/6)=1/24
11/17/2015 11:28:15 AM EDT
[#2]
Quote History
Quoted:
I believe it is the second answer you posted. You should only count the dice once.  (1/2)*(1/2)*(1/6)=1/24
View Quote

This is right.  1/2 for each coin and 1/6 for the one die, answer is 1/24.
11/17/2015 11:31:34 AM EDT
[#3]
Quote History
Quoted:
I believe it is the second answer you posted. You should only count the dice once.  (1/2)*(1/2)*(1/6)=1/24
View Quote


This is correct, they are three seperate and independent events. So (1/2)*(1/2)*(1/6)=1/24.

To get the 1/144 answer in the way that OP wrote it out would imply that the coin tosses coming up heads are contingent on the dice coming up 4.

11/17/2015 11:33:17 AM EDT
[#4]
If you're confused about probability, write out the outcomes.



HH1

HH2

HH3

HH4

HH5

HH6

HT1

HT2

HT3

HT4

HT5

HT6

TT1

TT2

TT3

TT4

TT5

TT6

TH1

TH2

TH3

TH4

TH5

TH6




There are 24.
11/17/2015 11:37:36 AM EDT
[#5]
I think the odds of getting two heads would be 1/3.
Possible coin combos:
2 heads
1 heads and 1 tails
2 tails

Multiply that by 1/6 th chance of rolling a 4.
11/17/2015 11:40:36 AM EDT
[#6]


Quote History
Quoted:



I think the odds of getting two heads would be 1/3.


Possible coin combos:


2 heads


1 heads and 1 tails


2 tails





Multiply that by 1/6 th chance of rolling a 4.
View Quote
No, the probability of getting 1 head and 1 tails is twice the probability of getting 2 heads or two tails--since there are two possible ways to get them.


1/4--two heads


1/2--one each


1/4--two tails





 
11/17/2015 11:41:04 AM EDT
[#7]
Quote History
Quoted:
I think the odds of getting two heads would be 1/3.
Possible coin combos:
2 heads
1 heads and 1 tails
2 tails

Multiply that by 1/6 th chance of rolling a 4.
View Quote


Except you can get 1 heads and 1 tails in two different ways.
11/17/2015 11:50:57 AM EDT
[#8]
Quote History
Quoted:

This is right.  1/2 for each coin and 1/6 for the one die, answer is 1/24.
View Quote View All Quotes
View All Quotes
Quote History
Quoted:
Quoted:
I believe it is the second answer you posted. You should only count the dice once.  (1/2)*(1/2)*(1/6)=1/24

This is right.  1/2 for each coin and 1/6 for the one die, answer is 1/24.



This is the correct answer.

For probabilities of multiple outcomes, you multiply the probability of each individual out come.
(1/2)*(1/2)*(1/6)=1/24

For the Quarter, probabililty of A happening (heads or tails) is
P(A)=X_A/T

where X_A is the number of ways A can happen, T is the total number of elementary events.

Thus: P(heads)=1/2, and P(tails)=1/2.

Same goes for a 6 sided dice (Assuming that it is numbered 1 trough 6 which is missing in the problem statement):
P(some_#)=1_# / 6_sides

The rule applies:
If two events A and B are independent then the probability that both event A and B will occur is equal to the product of their respective probabilities.

Therefore,
P (A_coin1, and B_coin2, and C_dice)=P(A)*P(B)*P(C)
or 1/2*1/2*1/6 = 1/24
11/17/2015 11:58:45 AM EDT
[#9]
Morning math question?

How dare you, OP!


A.W.D.
11/17/2015 12:00:48 PM EDT
[#10]
87
11/17/2015 12:05:49 PM EDT
[#11]
Quote History
Quoted:
Morning math question?

How dare you, OP!


A.W.D.
View Quote


Damn OP, you made me think

for an easier way to calculate use 2x2x6 = 24 or 1/24
11/17/2015 12:14:23 PM EDT
[#12]
Well, first you need to find a dice and two coins...
11/17/2015 12:28:45 PM EDT
[#13]
Quote History
Quoted:
Morning math question?

How dare you, OP!


A.W.D.
View Quote


Better than when she asked me, I was drunk and said 24 immediately then I guess I over thought it
11/17/2015 12:34:33 PM EDT
[#14]
Quote History
Quoted:
Well, first you need to find a dice and two coins...
View Quote


I think you mean a die and two coins.  Dice is plural.