Aiko had $20 dollars to buy candles returned 2 candles for which she had paid $4.75 each. Then she brought 3 candles for $3.50 each and I candle for $5.00. How much money Aiko have then?

Geometry answer picture question pls . reason and statements

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude

Which one is the correct answer, and why?