Answer : Option A

Explanation :

let the present age of the husband = h
present age of the wife = w
present age of the child = c
3 years ago, average age of husband, wife and their child = 27
$MF#%=>\text{Sum of age of husband, wife and their child before 3 years = }3 \times 27 = 81$MF#%
=> (h-3) + (w-3) + (c-3) = 81
=> h + w + c = 81+9 = 90 -------------------equation(1)
5 years ago, average age of wife and child = 20
$MF#%=>\text{Sum of age of wife and child before 5 years = }2 \times 20 = 40$MF#%
=> (w-5) + (c-5) = 40
=> w + c = 40+10 = 50 -------------------equation(2)
Substituting equation(2) in equation(1)
=> h + 50 = 90
=> h = 90 - 50 = 40
=>present age of the husband = 40