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# Random Event Probability Example

Random Event Probability Example 1
There are five red balls, three blue balls and two green balls mixed together in a bag. All balls are the same size and same material. When you pick one, what is the probability that you pick a green ball?
Solution
The probability that pick a green ball is:
Random Event Probability Example 2
Throw an unbiased dice with number 1 - 6 on each side once, and answer the following questions.
A. What is the probability of getting a face with number three?
B. What is the probability of getting an even number?
C. What is the probability of getting a number less than 3?
Solution A
Throw an unbiased cube with number 1 - 6 on each side once, the side that will face up may be 1, or 2, or 3, or 4, or 5, or 6. The total possible outcomes are 6, and all the possible outcomes are equally likely.
There is only one possible way for number 3 face up, that is, 3.
Solution B
There are 3 possible ways for even numbers face up, that is, 2, or 4, or 6.
Solution C
There are 2 possible ways of numbers less than 3. That is, 1, or 2.
Random Event Probability Example 3
Figure above is a turntable with 12 equal sector colored by red, yellow and blue. Spin the turntable once, if the pointer point to a colored sector, find the probability of the following events.
A. Point to the blue sector.
B. Point to red or yellow sectors.
C. Not point to yellow sector.
Solution A
There are total 12 equal sectors, in which 4 blue sectors.
Solution B
There are 5 red sectors and 3 yellow sectors.
Solution C
There are 3 yellow sectors, then sectors colored not yellow = total sectors - yellow sectors = 12 - 3 = 9 sectors.