Register to reply 
Logic questionby Peter Pan
Tags: logic 
Share this thread: 
#1
Nov703, 03:18 PM

P: 44

This question is making me angry. I think I know the answer but I have some coworkers that disagree.
Q. Sally is the 50th best student in her class and the 50th worst. How many students are in her class? A. 101, 100, 99, 50 I believe the anwser is 99 


#3
Nov703, 03:46 PM

P: 44

If sally is the 50th best student in her class, that means there are 49 student who are better. Also, if Sally is the 50th worst student, that means there are 49 that are worse than her 49 better + 49 worse + sally = 99 


#4
Nov703, 04:04 PM

P: 383

Logic question
Let's try something shorter. If Sally were 3rd best and also 3rd worst, the rankings would look like this:
best rank/worst rank/name 1st /5th /Cheryl 2nd /4th /Laura 3rd /3rd /Sally < 4th /2nd /Anne 5th /1st /Betty Note that 1st best simply means "the best" and 1st worst simply means "the worst". There are 5, or 2(3)1 class members. I don't think it makes any significant difference for 50th best and 50th worst. So, the number of members ought to be 2(50)1 = 99, and you, Peter, are correct. Of course, if some class members have equal rank, then more members are required. 


#5
Nov703, 04:35 PM

Sci Advisor
HW Helper
P: 2,537

Well, you also need to make sure there are no ties for 50th



#6
Nov703, 04:54 PM

P: 44

Assume to ties



#7
Nov2203, 12:11 AM

P: 124

The answer then, is 99. EDIT: When I subtract 1, I am subtracting Sally. 


#8
Nov2203, 06:25 AM

Emeritus
PF Gold
P: 1,192

well the way i worked it out is 50th best would mean 49 people in front of her were better, and 49 people in front of her were worse...so that's how i came up with a total of 50...but 99 also makes sense...



#9
Nov2203, 10:16 AM

P: 3,715




#10
Dec1103, 07:02 AM

P: 3

If she's the 50th best that would mean she's number 50 from the top.
If she's the 50th worst that would also mean she's the 50th from the top. Both are saying the same exact thing but they are worded different, really simple. Thanks 


#11
Dec1103, 02:19 PM

P: 44

"If she's the 50th best that would mean she's number 50 from the top.
If she's the 50th worst that would also mean she's the 50th from the top. Both are saying the same exact thing but they are worded different, really simple." What is your point? 


#12
Dec1203, 01:54 AM

P: 16

Theres no additional information to determine the number of students in Sally's class.
The statement you gave merely states that Sally is in the 50th position. 


#13
Dec1203, 11:49 AM

P: 44

50th best implies that 49 students have done better. 50th worst implies that 49 students have done worst. 


#14
Dec2903, 08:50 AM

P: 33

The statement simply implies that there are 49 students better than sally and 49 students worse, so the minimum number of students in her class in 99. As there can be infinite many students having the same grade as her, there can be infinte many students in tie for the 50th place. Thus the number of students in her class can be any of the natural numbers that is greater than or equal to 99.



#15
Dec2903, 09:11 AM

P: 454

As someone said, 99. As someone else said, you must make sure there are no ties. Also, there is the option that all people got the same score.



Register to reply 
Related Discussions  
Question on fuzy logic  Precalculus Mathematics Homework  1  
Logic Question!  General Math  4  
Logic Question  Calculus & Beyond Homework  1  
Logic question  Biology, Chemistry & Other Homework  0  
Propositional Logic Question  Engineering, Comp Sci, & Technology Homework  0 