That's three parts of a fish's mass plus four parts of a kilogram?
The weight of the fish: 3 / 4 (1-3 / 4) = 3 (kg)
What is (3 / 4) / 40
(3/4)/40=3/(40×4)
=3/160
0.25 is equal to 3 △ () = (): 40 is equal to ()%
0.25 is equal to 3 (12) = (10): 40 is equal to (25)%