Whether or not a "what" is needed after "than"

Solution 1:

I would like to slightly modify the sentences as: 1) lf you are overqualified for a particular job, you have more experience or training than needed. 2) The magnification is usually at least thirty times what is normally seen with the naked eye. (greater than... is redundant)

At the same time, your sentences: 1) lf you are overqualified for a particular job, you have more experience or training than what is needed. 2) The magnification is usually at least thirty times greater than what is normally seen with the naked eye.

...are not grammatically wrong, but for the bits of refinements.