If Books and More have earned 20% profit overall, then in film DVDs they made

Let total cost price of Books and More = $$RS. 100x$$

It is given that Books and More have earned 20% profit overall

=> Total S.P. = $$\frac{120}{100} \times 100x = 120x$$

Thus, S.P. of music CDs = $$\frac{35}{100} \times 120x = 42x$$

S.P. of books = $$42x + \frac{50}{100} \times 42x = 63x$$

=> S.P. of DVDs = $$120x - 42x - 63x = 15x$$

40% profit is earned in music CDs and 25% profit in books.

=> C.P. of music CDs = $$\frac{100}{140} \times 42x = 30x$$

and C.P. of books = $$\frac{100}{125} \times 63x = 50.4x$$

=> C.P. of DVDs = $$100x - 30x - 50.4x = 19.6x$$

=> Loss made on DVDs = $$19.6x - 15x = 4.6x$$

$$\therefore$$ Loss % on DVDs = $$\frac{4.6 x}{19.6 x} \times 100 = 23.46 \%$$