<PRE><B>Question 197961</B>
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.
</PRE>