Question

When I was married 10 years ago my wife is the 6th member of the family. Today my father died and a baby born to me.The 2 age of my family during my marriage is same as today. What is the age of Father when he died ?
A) 50 yrs
B) 60 yrs
C) 70 yrs
D) 65 yrs

Answer 1

Answer:   B) 60 yrs 

Explanation:

Let the Father be x years when he died

Average Age 10 years ago be A

Total Age 10 years ago = 6*A

Total Age after 10 years(Just before father's Death) = 6A + 6*10 = 6A + 60

Father Died and Baby was born => the Total number of people in the family is Same (6) 
Baby born today so age of baby = 0

(6A +60 - x)/6 = 6A/6 
=> A + 10 -(x/6) = A 
=> x/6 = 10 
=> x = 60

Therefore we can conclude that the father was 60 years old when he died.

Answer 2

When I was married 10 years ago my wife is the 6th member of the family. Today my father died and a baby born to me.The 2 age of my family during my marriage is same as today. What is the age of Father when he died ?
A) 50 yrs
B) 60 yrs
C) 70 yrs
D) 65 yrs

Answer: B) 60 yrs

Explanation:

Lets take the age of father 10 yrs ago as x.
Then rest of the 5 members 10 yrs ago as y.

Now the mean age 10 yrs ago is = (x + y)/6 --(1)

and now as father is dead and all the ages of the other 5 members has risen by 10 each.

So mean age now =(y + 5(10))/6 ---(2)

Equating (1) and (2): (x+y)/6 = (y+50)/6

Be solving the above, we get x = 50.

So present age when he died

= x + 10

= 60 yrs.