Select a counter-example that makes the conclusion false.. you select three marbles from a bag and each of them is black.. conclusion: all the marbles in the bag are black.. counterexample:

Counterexample : You select three marbles from a bag and at least one of them is not black

Step-by-step explanation:

Counterexample is referred to as an example that contradicts or opposes an idea or theory.

So, in this case to find a counterexample, we need to find an example that opposes or makes the conclusion false. The conclusion is : All the marbles in the bag are black so we need an example that shows atleast one marble is not black.

So, we choose the required counterexample as " You select three marbles from the bag and atleast one of them is not black"

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step-by-step explanation:

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