SOLUTION: If 6 numbers are drawn promiscuously from the numbers 1 to 49 inclusive,how do we find the probability of the selection containing exactly one run of three consecutive numbers. E

Algebra.Com
Question 442709: If 6 numbers are drawn promiscuously from the numbers 1 to 49 inclusive,how do we find the probability of the selection containing exactly one run of three consecutive numbers.
E G 123 8 28 38,
or
4 9 15 16 17 49.
My book,Random Variables,D Stirzaker, offers a solution but it is clear that the author has made a mistake .morleyken@rocketmail.com.Thank you.



Answer by swincher4391(1107)   (Show Source): You can put this solution on YOUR website!
When drawing your first number, you have a 1/49 chance of drawing any number.
If you draw a 1: You have a 1/48 chance of drawing a number consecutive to it.
If you draw a 49: You have a 1/48 chance of drawing a number consecutive to it.
If you draw anything else: You have a 1/24 chance of drawing a number consecutive to it.
---------------------------------------------------------------
2nd draw:
If you have drawn a 1, and then a 2, you have a 1/47 chance of drawing a number consecutive to it.
If you have drawn a 49, and then a 48, you have a 1/47 chance of drawing a number consecutive to it.
If you have draw something other than that, then you have a 4/47 chance of drawing a number consecutive to it.
For instance you have drawn 11,17
10, 12, 16, 18 are all candidates.
We also excluded ... so
4/44 = 1/11 chance.
-----------------------------------------------------------------
On our third draw:
probability of 1,2,3 = (1/49)(1/48)(1/47)
probability of 49,48,47 = (1/49)(1/48)(1/47)
Anything else: 6/46 = (3/23)

-------------------------------------------------------------
We now have one run.
probability of 1,2,3 and then no run = (1/49)(1/48)(1/47)(45/46)(39/45)(35/44)
Same probability with 49,48,47 and then no run
Our anything else probability is: (1/49)(1/24)(4/47)(3/23)(37/45)(33/44)
probability(B) = (61465/10068347520)
probability(C) = (61465/10068347520)
probability(A) = (14652/2517086880)
P(A or B or C) = 2* (61465/100068347520) + 14652/2517086880)
= 2* (61465/100068347520) + (14652/2517086880)

= (18682943161 / 2650260149893440)
Hopefully... lol

RELATED QUESTIONS

in the 6/49 lottery,six different numbers must be selected between 1 through 49... (answered by Alan3354)
Classic Lotto Prize Payout Table... (answered by stanbon)
How many numbers from 1 to 200 inclusive are equal to the cube of an integer? (answered by Fombitz)
The numbers from 1 to 11 are drawn at random. Find the probability that the even numbers... (answered by Boreal)
In a certain lottery, 6 numbers between 1 and 11 inclusive are drawn. These are the... (answered by Solver92311)
Please throughly explain how to solve this problem: To win the Lotto in the state of... (answered by checkley75,Edwin McCravy)
How many different three-digit even numbers can be formed from the set of integers from 1 (answered by Edwin McCravy)
How many members are there in the set of even numbers from 60 to 120... (answered by jsmallt9)
I am looking for assistance solving this problem: In a certain lottery, 4 different... (answered by stanbon)