The question does not state if you require the amount reduced by or the final figure left after the reduction.
There are two things to remember hear.
1: We are talking about a change that is a reduction. So the answer
2: The symbol % is a bit like units of measurement and that is worth
This is a reduction so the amount it is reduced by is:
There are several paths that can be followed now but they all lead to the same point.
With practice you could some of this in your mind.
But this a reduction so the answer to this part is: