A friend of mine went for a teaching job, and met the other candidates.
At the end of the interview they asked her "which of the candidates do you think would be best for the job?"
She was mentally weighing up the others when she realised the answer had to be "ME...because....".
If they five you a chance to sell yourself, take it.
If they ask "what are your weak points?" it's more of a problem, you don't want to sound arrogant, but you don't want to admit to major shortcomings. I suppose if you could turn it round to something positive.."I didn't get GCSE maths at school, but I'm taking evening classes"