Two Plus Two Newer Archives

Two Plus Two Newer Archives (http://archives1.twoplustwo.com/index.php)
-   Probability (http://archives1.twoplustwo.com/forumdisplay.php?f=27)
-   -   Straight Forward Probablility Question (http://archives1.twoplustwo.com/showthread.php?t=130884)

pocketjacks 06-05-2006 01:12 PM

Straight Forward Probablility Question
 
There are 20 students in your gym class. Your teacher divides the class into two equal softball teams. Your team draws names one by one to determine the batting order. What is the probability that 1 of the 7 freshman on the team will be chosen first, in any order?


Related to the top question.

find the probability that 3 of the 7 freshmen will be chosen last, in any order.

Any help and explanation would be very much appreciated.

Thanks in advance!

toms2866 06-10-2006 01:57 AM

Re: Straight Forward Probablility Question
 
Here are the answers for your homework assignment...

Question 1: 10 players, 7 are freshman. Chance a freshman picked first = 7/10.

Question 2: Same chance as 3 freshman picked first = 7/10 * 6/9 * 5/8.

toms2866 06-10-2006 02:03 AM

Re: Straight Forward Probablility Question
 
If you meant 7 freshman in the 20 students...

Question 1: 10 players, 3.5 are freshman. Chance a freshman picked first = 3.5/10.

Question 2: 3.5/10 * 2.5/9 * 1.5/8

AaronBrown 06-10-2006 02:17 PM

Re: Straight Forward Probablility Question
 
I agree with the first two answers, which assume 7 out of the 10 students on the team are freshmen. If we assume 7 out of 20, the answer to question 1 is correct, but question 2 is not.

The division into two teams is just a distraction if we are given the number of freshmen in the 20 person gym class. The chance than the last three players drawn for one specific team are freshmen is 7/20 * 6/19 * 5/18.

toms2866 06-13-2006 07:53 PM

Re: Straight Forward Probablility Question
 
[ QUOTE ]
the answer to question 1 is correct, but question 2 is not.

[/ QUOTE ]
You're right.


All times are GMT -4. The time now is 04:05 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.