It is given that f: {1, 3, 4} → {1, 2, 5} and g: {1, 2, 5} → {1, 3} be given by

f = {(1, 2), (3, 5), (4, 1)} and g = {(1, 3), (2, 3), (5, 1)}. Then,

gof(1) = g (f(1)) = g (2) = 3

gof(3) = g (f(3)) = g (5) = 1

gof(4) = g (f(4)) = g (1) = 3

Therefore, gof = {(1,3), (3,1), (4,3)}