1. The problem statement, all variables and given/known data Prove that 1+1+1/2!+1/3!+....+1/n! < 3 2. Relevant equations None 3. The attempt at a solution Any suggestion how can I start? I dont want the solution that 1+1+1/2!+1/3!+...+1/n!=(1+1/n)^n and lim (1+1/n)^n = e<3 since the 2nd part is to prove (1+1/n)^n <3 . I don't want a solution. I just want to know how to start with it.