Dear Reader, below are 4 preparatory age related problems. These kinds of questions can be expected on TCS and other similar company papers.

Question 1

Four years ago, the average age of Deena and Prakash was 21 years. With Harish joining then now the average becomes 25 years. How old is Harish now?

a) 28 years b) 26 years c) 24 years d) 25 years.

Answer : d) 25 years.

Solution:

Let the present age of Deena, Prakash and Harish be A, B and C respectively.
4 years ago, the average age of Deena and Prakash was 21 years.
(i.e.) (A - 4 + B - 4) / 2 = 21
=> A + B = 50 -------- (1)
But now, the average age of Deena, Prakash and Harish is 25 years.
(i.e.) (A + B + C) / 3 = 25
=> A + B + C = 75 ------- (2)
(2) – (1) => C = 75 - 50 = 25.
Hence, the Present age of Harish is 25 years.

Question 2

The present age of Harini’s father is 4 times the present age of Harini. And the age difference of Harini’s father and mother is 5 years. Five years ago, the sum of all the three person’s age was 70 years. What is the present age of Harini’s father?

a)44years b) 40years c) 50years d) 48years

Answer : b) 40

Solution:

Let the Present ages of Father, Mother and Harini be F, M and H respectively.
Present age of Father = 4 * Present age of Harini
i.e. F = 4H ------- (1)
Age difference between Harini’s Parent's = 5
i.e. F – M = 5 -----------(2)
Five years ago, the sum of ages of Father, Mother and Harini is 70 years
i.e. F – 5 + M – 5 + H – 5 = 70
=> F + M + H = 85 -------- (3)
(2) + (3) => 2F + H = 90 ----- (4)
Substitute (1) in (4), we get H = 10.
Then F = 4*10 = 40.
Therefore the present age of Harini’s father is 40 years.

Question 3

Haritha told her friends that if she add ten times her age ten years from now to five times her age five years ago is same as the 20 times of her current age. How old Haritha will be ten years from now?

a)15 years b) 20 years c) 23 years d) 25 years

Answer : d) 25 years

Solution:

Let the age of Haritha be X.
Then, 10 times her age after 10 years + 5 times her age before 5 years = 20 times her present age.
i.e. 10 * (X + 10) + 5 * (X - 5) = 20 * X
15X + 75 = 20X
5X = 75
X = 15
Hence, Haritha’s Present age is 15 years.
So, after 10 years, Haritha’s age will be 25 years.

Question 4

Three years ago, the ages of Geetha, Reena and Surya are in the ratio of 3:4:5. Three years hence, the sum of their ages is 78. What is the age of Reena at present?

a)18 years b) 23 years c) 28 years d) 20 years

Answer : b) 23 years

Solution:

Let the ages of Geetha, Reena and Surya 3 years ago be 3X, 4X and 5X respectively.
After 3 years, the sum of their ages is 78.
i.e. (3X + 3) + 3 + (4X + 3) + 3 + (5X + 3) + 3 = 78
12X = 60
X = 5.
Hence, Reena’s present age is 4X + 3 = 4(5) + 3 = 23 years.