Isnt as easy

A. Can you solve this problem in a few minutes?

1.Nah, it isn't as easy a problem to solve in a few minutes.

2.Nah, it isn't as easy to solve it in a few minutes.

3.Nah, it isn't easy to solve it in a few minutes.

Can I say 1,2,3 as an answer to sentence A?

I've often seen the part following "as easy" such as "as you think" omitted like in 2, so I'm asking whether they all can be considered correct and grammatical as a respond to A.

I think I can say 2 if in a situation everyone can figure out "as you think" is implied as in "It isn't as easy (as you think) to solve it in a few minutes, so I think even without adding the part, 2 can be correct because in the situation they can figure out what is implied.

And as a side question,
Could there be a situation where I can say "B.I have never painted my car as red" instead of "C. I have never painted my car red"?