Question

Which of the following is a counter example of the statement? If 2n + 4 < 20. then n < 6.

Answer 1

Can you solve for n in the hypothesis of the statement?
2n + 4 < 20

You could then see if there's a value there that's not covered in n<6

Answer 2

Oh, "which of the following."
If you're given choices, try looking for the one that works in 2n + 4 < 20 that does not work in n < 6.

Answer 3

Well, you could chose a value for n equal to or larger than six that still makes the statement true. Six or seven would be my choices.....