Aptitude - Average - Discussion

3 years ago, average age of husband, wife and their child = 27,
=> Sum of age of husband, wife and their child before 3 years = 3 * 27 = 81,
=> (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,
=> Sum of age of wife and child before 5 years = 2 * 20 = 40,
=> (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.

i.e., Present age of the husband = 40.

Can anyone please help me with this question?

The average of a couple was 24 years when the child was just born. What will be the age of the father when the child reaches to the age of the mother when she gave him the birth?

Thanks @Ramya.

The age of mother and father when the child was just born is 24/2=12.
When the child reaches to the age of the mother means when it will reach 12 years,
Father age is 12+12=24.

Can anyone say is this answer is correct?

Thank you for explaining the answer.

3 year ago(h+w+c) = 27 * 3 = 81.
5 year ago=81-6 = 75(2h+2w+2c).
5 year ago(w+c) = 2 * 20 = 40.
5 year ago h = 75-40 = 35.

And the present age is 40 years of the husband.

First separate the question:

In the first part, The average age of husband, wife and their 3 years ago was 27 years, so;

Lets consider Husdand age = x-3(-3 because it was 3 years ago from the present age)

Wife's age= y-3 and son's age = z-3,
Average= x-3+y-3+z-3/3=27,
x+y+z=81 ------> (1)

Second part of the question.
That of wife and the child 5 years ago was 20 years, so;
Wife age years ago is y-5,
Sons age is z-5,
Avg= y-5+z-5=20,
y+z=30---> (2)

Equating (1) and (2)
Then x=40.

The average age of a husband and wife at the time of their marriage was 25 years. A son was born to them exactly 2 years after their marriage and the average present age of all three is 24 years. How many years have been passed by the couple?
Can anyone explain the answer of this?

27*3=81,
81+9=90,
5year ago =formula( average age*2),
So, 20*2=40,
40+10=50.
Husband age 90 - 50 = 40.

@Kanchan Shah.

Can you give the explanation little briefly?