Question

Which is a counterexample that disproves the conjecture?

If n is a positive integer, then 2n – 1 is a prime number.
n = 6
n = 5
n = 3
n = 2
answer: n=6

Answer 1

2*6-1

Answer 2

nope, 2*6 -1=11, it is a prime.

Answer 3

try n=5

Answer 4

so it n=5 because I got 9

Answer 5

yes. because 9 is not a prime, hence you can use it to debut the statement.

Answer 6

thanks