What is the net price factor for trade discounts of 25/15/10? (Points : 2.5)

I am not sure how your text defines "net price factor"

but the equivalent single discount is
(.75)(.85)(.9)
= .57375
or a discount of 57.375 %
or
the percentage of the original cost you would have to
pay would be 42.625 %
which is equivalent to .42625 of the original cost