Which one is correct?

[Anonymous]

If you had prepared for the examination last night, __________.

a) you wouldn't find any difficulty now.
b) you would find no difficulty now.

I think both expression is right, but the answer is only b).
Why is that?

Always appreciate your help.

 

[Tdol]

I think both are fine, though I'd probably use 'have'instead of 'find'. ;-)