- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 3. Probability Concepts
- Subject 10. Principles of Counting
CFA Practice Question
If there are 30 entries in a "best of breed" dog show, in how many ways can 1st, 2nd, and 3rd place be awarded?
A. 4060.
B. 30.
C. 24,360.
Correct Answer: C
30P3 = 30!/(30 - 3)! = 24,360
User Contributed Comments 8
User | Comment |
---|---|
nsmwaura | But I thought order matters in this case. Dog A, B & C for 1st 2nd and 3rd respectively is not the same as dog b, a and c |
charlie | that's why the answer uses P not C to calculate! |
krisscfa | Its actually Different.... Step 1:- 30 C 3= 4060. Step 2:- Dogs can be arranged in 6 ways in 1st ,2nd and 3rd places So the answer is 4060*6=24,360 |
Rivermax | 1st - any of the 30 2nd - any of the remaining 29 3rd - any of the remaining 28 => 30 X 29 X 28 = 24360 |
prachirp | I think very logical and easy to understand. Thanks Rivermax. |
hoyleng | when to use nPr n when to use nCr? pls help. thanks |
gulfa99 | npr when order matter and ncr vice versa |
chipster | I like Rivermax explanation but on BAII 30-->2nd-->nPr-->3--> = gives answer |