I've been posting some confusing problems, that i can't figure out. Please help if you can.

a.) Use (4) to show that if Sn is the nth partial Sum of the harmonic series then Sn <= 1 + Ln n

b.) The harmonic series diverges, but it does so very slowly. Use part (a) to show tat the sum of the first term is less than 15 and the sum of the first billion terms is less 22.

i'm having alot of trouble with this one.