Step-by-step explanation:
Let the man's current age be given as M
Let his son's age be given as A
Let his daughter's age be given as D
From the question
S= 3+D.........(1)
In one year,
M+1 = 6D.....(2)
In sixteen years,
M+16 = (S+16) + (D+16).......(3)
From (1) to (3)
M+16 = (3+D+16) + (D+16)
M+16 = 2D + 35
M = 2D + 19........(4)
From (4) to (2)
(2D + 19) + 1 = 6D
2D + 20 = 6D
.....
Complete later