Aptitude - Average - Discussion

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?

Your explanation is superb, Thanks @RAMYA.

The average age of three persons is 18. If two of them are included then the average age becomes 20. If the age of 1st is 17 then find the age of the remaining persons.

Can anyone tell me?

The average age 3 years ago = x+y+z/3 = 27,
Age of wife and son 5 years ago is x-2+y-2/2 = 20,
Hence x+y = 36.

36+z/3 = 27,
z=45.

Hence present age should be 45+3 which is 48.

Can someone tell me why this is wrong?

A person has a wife and three children. The average age of his parents is 70 which is 40 to his age and his wife is 15 from the average age of her children. What is the average age of the whole family?

Can anyone solve this?

Thanks for providing the easiest solution @Loverboy.

3 years ago, their avg is 27.
((h-3) + (w-3) + (c-3) ) /3 = 27.

h+w+c = 90. (present).
5 years ago w & c is 20.

((w-5) + (c-5) ) /2 = 20.

w+c=50. (present).
(h+w+c) - (w+c) = 40.

h = 40 years.