SOLUTION: If you asked three strangers about their birthdays, what is the probabilty..
a. All were born on Wednesday
b. All were born on a different day of the week
c. None were born on
Algebra.Com
Question 197961: If you asked three strangers about their birthdays, what is the probabilty..
a. All were born on Wednesday
b. All were born on a different day of the week
c. None were born on Saturday
Canm I get an explaination of how you got to the answer?
Found 2 solutions by stanbon, solver91311:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
If you asked three strangers about their birthdays, what is the probabilty..
a. All were born on Wednesday
P(any one of them was born on Wednesday) = 1/7
P(all three were born on Wednesday) = (1/7)^3 = 1/343
-------------------------------------
b. All were born on a different day of the week
P(all on different day) = 1 - [P(all on same day) + P(2 born on same day)]
----
P(all born on same day) = 7(1/343) = 1/7^2 = 1/49
P(2 born on same day) = 7(1/7)^2(6/7) = 0.12245
--
Therefore P(all on different day = 1-[(1/49) + 0.12245] = 0.857...
------------------------------------------------------------------------
c. None were born on Saturday
P(none born on Saturday) = (6/7)^3 = 0.6297...
------------------------------------------------------
Cheers,
Stan H.
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
All Wednesdays:
There are seven different days in the week, so the probability that one person is born on a given day is 
. Since each of the three birthdays is an independent event, the total probability is the product of the three individual probabilities:
\left(\frac{1}{7}\right)\left(\frac{1}{7}\right))
Different day of the week:
The probability that the first guy is born on any one of the 7 days in the week is certainty, or 1. The probability that the second guy was born on a different day is the number of days unused so far, or 6 divided by the number of possible days, or 7. The probability that the third guy was born on yet a different day is calculated the same way, this time 5 divided by 7. Again the total probability is the product:
\left(\frac{5}{7}\right))
None on Saturday:
6 out of 7 ways not to be born on Saturday, so:
\left(\frac{6}{7}\right)\left(\frac{6}{7}\right))
By the way, you get to do your own arithmetic.
John
RELATED QUESTIONS
what is the probability of all three strangers born on... (answered by stanbon)
Three students are chozen at random .Find the probability that all three were born on... (answered by robertb)
Assume that births are distributed evenly over the seven days of the week. If you ask 3... (answered by vleith,stanbon)
Leading men. Bob hope was born 2 years after Cark Gable and 2 years before Henry Fonda. (answered by Edwin McCravy)
Bob Hope was born 2 years after Clark Gable and 2 years before Henry Fonda. In 1951,... (answered by checkley75)
Bob was born 2 years after Clark and 2 years before Henry. In 1951, after all three of... (answered by ankor@dixie-net.com)
Leading men. Bob Hope was born 2 years after Clark Gable and 2 years before Henry Fonda. (answered by jojo14344)
Bob Hope was born 2 years after Clark
Gable and 2 years before Henry Fonda (Doubleday... (answered by PRMath)
Bob Hope was born 2 years after Clark Gable and 2 years before Henry Fonda. In 1951,... (answered by josmiceli)