Practice UPSC CSAT previous year questions from 2011–2026 classified underProblems Based on Ages. Review the original question, four options, correct answer and explanation for every PYQ.
3 questions • 2011–2026
A father said to his son, "n years back I was as old as you are now. My present age is four times your age n years back". If the sum of the present ages of the father and the son is 130 years, what is the difference of their ages?
Let the son's present age be s and the father's be f. From f−n=s and f=4(s−n), together with f+s=130, solving gives a 30-year age difference.
The sum of the ages of 5 members comprising a family, 3 years ago was 80 years. The average age of the family today is the same as it was 3 years ago, because of an addition of a baby during the intervening period.
The sum of the ages of 5 members comprising a family, 3 years ago was 80 years. The average age of the family today is the same as it was 3 years ago, because of an addition of a baby during the intervening period. How old is the baby?
Three years later the original five members total 95 years. The unchanged average is 80/5=16, so six members today must total 96. The baby is therefore 1 year old.
A father is nine times as old as his son and the mother is eight times as old as the son. The sum of the father’s and the mother’s age is 51 years. What is the age of the son?
Let the son's age be x. Then 9x+8x=51, so 17x=51 and x=3.
Attempt questions one by one with UPSC-style marking and immediate explanations.