What are your strengths?
 

You should always remember that even if your strength is not business related, find a way to relate it to work. Tell your positive points related to the job.

For example -these may be some great answers:

My main strengths are the ability to use my own initiative to take on challenges. I am always proactive at what I do and that keeps my mind simulated and focused.
My greatest strengths would be my intelligence and thoughtfulness. I believe that in every work environment you need to process every step and be detailed in your work.
My time management skills are excellent and I'm organized, efficient, and take pride in excelling at my work.
I always understand the value of time and I am always able to innovate. I listen to advice from others.
My greatest strength is my ability to focus on my work. I'm not easily distracted, and this means that my performance is very high.