Counter Example

Definition of Counter Example

Counterexample is an example that is used to disprove a statement.

Example of Counter Example

    The opposite of a number is always positive.
    Counterexample for the above statement: The opposite of 2 is - 2, a negative number.

Video Examples: Geometry - Inductive Reasoning & Counterexamples


Solved Example on Counter Example

Ques: Which of the following is a counterexample of the statement, "The perimeter of a rectangle can never be an odd number"?

    Choices:
    A. Length of a rectangle is 3.25 in. and width is 5.25 in.
    B. Length of a rectangle is 10 in. and width is 7 in.
    C. Length of a rectangle is 6.5 in. and width is 4.5 in.
    D. Length of a rectangle is 9 in. and width is 5 in.
    Correct Answer: A

Solution:

    Step 1: The counterexample that disproves the given statement is:
    'Length of a rectangle is 3.25 in. and width is 5.25 in.'

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