Answer
Find out the how much of her total sales did she donate .
To prove
Let us assume that the songstress gives away of the sales of her signature fragrance collection to her charity be x.
Formula

As given
songstress gives away 25 percent of the sales of her signature fragrance collection to her charity.
Last month her sales were 1200.
Thus
Percentage = 25 %
Total value = 1200
Put in the formula



x = 300
Therefore songstress gives away of the sales of her signature fragrance collection to her charity be 300 .