Math Is Fun Forum

(1)  Use induction to show 2^n > 3n for n > 4

(2) (a) Show 3 times 5 < 2^5

(b) Assume 3n < 2^n (n > 5) : add 3 to each side and in a couple of steps you have 3(n+1) < 2^ (n+1)

That should do it.