Probability

Definition of Probability

• Probability is a numerical measure of the likelihood of occurrence of an event. The value of probability lies between 0 and 1.
• If all outcomes of an experiment are equally likely, then the probability is given by,

Probability of an event = .

 

Examples of Probability

• The probability to pick a blue marble from a basket containing 10 blue marbles is 1.
• Suppose you toss a fair coin. Then the probability of tossing a head or tail is  

Solved Example on Probability

A basket contains 30 apples, 20 pears and 10 peaches. What is the probability that the first piece of fruit taken from the basket will be a peach?

Choices:

A.

B.

C.

D.

Correct Answer: C

Solution:

Step 1: Total number of fruits in the basket = 30 + 20 + 10 = 60.

Step 2: Number of peaches in the basket = 10.

Step 3: The probability of taking a peach from the basket = .             

[From the definition.]

Related Terms for Probability

• Event
• Outcome

 

Additional Links for Probability

• Click here for samples
• Back to Mathematics Dictionary