- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 3. Probability Concepts
- Subject 10. Principles of Counting
CFA Practice Question
A network executive has to decide on the programming line-up for Thursday night. If there are ten shows to choose from, how many six-show line-ups are possible?
B. 1,000,000
C. 151,200
A. 60
B. 1,000,000
C. 151,200
Correct Answer: C
10P6 = 10!/(10 - 6)! = 151,200
User Contributed Comments 12
User | Comment |
---|---|
dipta | The question is not clear on whether ordering the shows matter |
kunam | the word line-up is the key |
kunam | yeah...Unclear... if the order is important then it needs to be 10C6 instead of 10P6... |
kunam | Oops.. 10 P 6 is correct given the word "line-up". Here order is important. so this is a permutation.. |
KD101 | This is a tricky question if you are from non-english speaking countries. The word line-up is a hint |
roninacolyte | survivor....apprentice...fear factorial... |
rfvo | Come on people!! use your calculators thats what their meant for...here i'll make it easy for you BA II 10 2nd nPr 6 =151 200 Simple...and order matter in this case. |
viannie | Line-up so permutations. 1st line-up: 10 shows to choose from 2nd line-up: 9 shows to choose from (since 1 already selected and can't be selected more than once) 3rd line-up: 8 shows etc ... |
panvino | Thanks rfvo - and just saw there is also the function for combination formula - nPr is 2nd + sign, nCr is 2nd - sign. |
Kennyk11 | Just to be logical, you wouldn't want to air the same program in a row, which makes the orders matter, hence the use of nPr instead of nCr. Well, that is, unless a program is super popular, in which case, keep showing it! :p |
ashish100 | Thanks rfvo!! Your motivation is much appreciated! |
fmunteanu | I can see that people here try to find various explanations for the use of the permutation formula instead of the combination one. That's very good but that doesn't change the fact that the Q is poorly worded / misleading.. |