exercises

I have to rewrite these sentences in the mentioned pattern for homework. Please help me out a bit. I am including three options a), b), c) as answer; please tell me which one would be correct.

Q 1. Had I known how to study, I would have scored better. (Begin with "I would have scored better provided...)

Ans - a) I would have scored better provided I knew how to study.
b) I would have scored better provided that I knew how to study.
c) I would have scored better provided I had known how to study.

Q 2. I had to work for two hours to finish the job. (Begin with "It took....")

Ans - a) It took me two hours of work to finish the job.
b) It took me two hours to finish the job.