Disproof by Counter Example (AQA A-Level Mathematics): Flashcards

One counterexample collapses an argument

One

All, every, for every

$6$ (multiple of 2, not 4)

$n = 4$

$15$

$15 = 5 \times 3$ (not prime)

$2$

$2$ is prime and even

Yes, one is enough to disprove