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Logic & numbers

All roses are plants. Some plants are tall. Must any roses be tall?

No. The conclusion does not follow.

The answer

No. The conclusion does not follow.

The idea

To disprove a guaranteed conclusion, find one case where the premises hold and the conclusion fails.

An example

Picture a garden with two short roses and one tall tree. Every rose is a plant, and some plants are tall, but no rose is tall. This counterexample satisfies both premises.

Try it

Write a new premise that would guarantee at least one tall rose. Check that you have not merely restated an unrelated fact.

More context

The tall plants could all be trees while every rose is short. One possible counterexample is enough to show the conclusion is not guaranteed.

the 102 platform · Constructed puzzle

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