- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 3. Probability Concepts
- Subject 1. Introduction
CFA Practice Question
Suppose a traffic light cycles through green for 180 seconds, then yellow for 10 seconds, and then red for 110 seconds. Find the probability that at a certain time the light is green. Find the odds in favor of the light being green.
B. 0.60; 3:5
C. 0.60; 3:2
A. 0.01; 3:5
B. 0.60; 3:5
C. 0.60; 3:2
Correct Answer: C
Odds: 180:(110 + 10) = 3:2
p = 180 / (180 + 110 + 10) = 0.6
Odds: 180:(110 + 10) = 3:2
User Contributed Comments 7
User | Comment |
---|---|
Renaud1807 | Can someone explain the odds? And how to find it with the BAII? |
Beret | Odds of a to b means probability E = a/(a+b) = 0.60, Here a = 180 and b = 10 + 110 |
Bobokoko | prob of success (0.6)/prob of failure (0.40)= 1.5/1 or to lose the decimal, 3:2 |
stitcher | Prob of Green P(G) = 180/300 =.6 consider binomial with P(G) as success 1-P =.4 Odds for are P(G)/P(G c) = 6/4 3/2 3:2 |
Sanghamitra | thanks all for making it so clear! |
abhishekcj | why not 3:5 |
s214111 | 60/1-60=60/40=3/2 or 3:2 |