Theory & Concepts
SSC CGL Problems on Ages Questions, Formulas & Tricks
Prepare Problems on Ages for SSC CGL with formulas, short tricks, solved examples, practice questions, PYQs, and free PDF notes for faster exam preparation.
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Practice Notes
20 min readDifficulty: Beginner
"Ages" is one of the most scoring topics in the Ssc cgl arithmetic section. It relies on a blend of simple linear equations and the "Constant Difference" rule that applies to all people over time.
The secret to mastering this chapter is avoiding complex algebra. By using the ratio balancing method, you can solve almost any CGL age problem in under 15 seconds.
Learning path
- Constant age difference logic
- Ratio balancing shortcut
- Timeline jumps (Past vs Future)
- 10 standard solved problems
- Average age of a group
1. The constant difference rule
The core logic
"If A is 5 years older than B today, A will always be 5 years older than B—whether it was 10 years ago or 50 years in the future."
This means the difference between ratio terms must be balanced across time periods.
2. Timeline transitions
Past (n years ago)
Present Age
Future (n years later)
3. 10 Solved examples
Question 01Standard pattern
The age of father is 4 times that of his son. 5 years ago, the father was 7 times as old as his son. Find their present ages.
40 and 10
36 and 9
32 and 8
44 and 11
Correct answer: a) 40 and 10
Solution
Let son's age be \( x \). Father's age = \( 4x \).
5 years ago: \( 4x - 5 = 7(x - 5) \).
Calculation: \( 4x - 5 = 7x - 35 \implies 3x = 30 \implies x = 10 \).
Present ages: Father = \( 40 \), Son = \( 10 \).
Question 02Standard pattern
The ratio of current ages of A and B is 3 : 4. After 10 years, this ratio becomes 4 : 5. Find their current ages.
30 and 40
15 and 20
21 and 28
12 and 16
Correct answer: a) 30 and 40
Solution
Current Ratio: \( 3 : 4 \). Future Ratio (10 yrs): \( 4 : 5 \).
Gap in units for both is \( 1 \) (\( 4-3=1 \) and \( 5-4=1 \)).
This 1 unit corresponds to 10 years.
Ages: \( 3 \times 10 = 30 \) and \( 4 \times 10 = 40 \).
Question 03Standard pattern
Mother is 24 years older than her daughter. In two years, mother's age will be twice the age of her daughter. Present age of daughter?
22 years
14 years
18 years
20 years
Correct answer: a) 22 years
Solution
Let daughter = \( x \). Mother = \( x + 24 \).
In 2 years: \( (x + 24) + 2 = 2(x + 2) \).
\( x + 26 = 2x + 4 \implies x = 22 \).
Question 04Standard pattern
The ratio of ages of A and B 10 years ago was 1 : 3. Their current ratio is 3 : 5. What is the sum of their present ages?
40 years
30 years
50 years
45 years
Correct answer: a) 40 years
Solution
10 yrs ago: \( 1:3 \) (Diff 2). Now: \( 3:5 \) (Diff 2).
Difference in A's units: \( 3 - 1 = 2 \) units.
2 units = 10 years \( \implies 1 \text{ unit} = 5 \text{ yrs} \).
Present ages: \( 15 \) and \( 25 \). Sum = \( 40 \).
Question 05Standard pattern
A father said to his son, 'I was as old as you are at the present at the time of your birth'. If the father's age is 38 years now, the son's age five years back was:
14 years
19 years
33 years
38 years
Correct answer: a) 14 years
Solution
Father's age at birth = Son's current age \( S \).
Equation: \( 38 - S = S \implies 2S = 38 \implies S = 19 \).
Five years ago: \( 19 - 5 = 14 \).
Question 06Standard pattern
Sum of ages of 5 children born at intervals of 3 years is 50 years. Age of the youngest child?
4 years
8 years
10 years
12 years
Correct answer: a) 4 years
Solution
Let ages be \( x, x+3, x+6, x+9, x+12 \).
Sum: \( 5x + 30 = 50 \implies 5x = 20 \implies x = 4 \).
Question 07Standard pattern
The age of a man is 3 times the sum of ages of his two sons. In 5 years, his age double the sum of their ages. Find his current age.
45 years
30 years
50 years
35 years
Correct answer: a) 45 years
Solution
Let sum of sons be \( S \). Man = \( 3S \).
In 5 yrs: \( 3S + 5 = 2(S + 10) \) (since there are 2 sons).
Calculation: \( 3S + 5 = 2S + 20 \implies S = 15 \).
Man's present age = \( 3 \times 15 = 45 \).
Question 08Standard pattern
The product of the ages of Ankit and Nikita is 240. If twice the age of Nikita is more than Ankit's age by 4 years, what is Nikita's age?
12 years
15 years
10 years
20 years
Correct answer: a) 12 years
Solution
Let \( A \times N = 240 \) and \( 2N - A = 4 \implies A = 2N - 4 \).
\( (2N - 4)N = 240 \implies 2N^2 - 4N - 240 = 0 \).
Result: \( N = 12 \).
Question 09Standard pattern
The current ratio of ages of husband and wife is 4:3. After 4 years, it will be 9:7. Current ages?
32 and 24
40 and 30
28 and 21
36 and 27
Correct answer: a) 32 and 24
Solution
Ratio 1: \( 4:3 \) (Diff 1). Ratio 2: \( 9:7 \) (Diff 2).
Balance: \( 8:6 \) and \( 9:7 \).
Gap = 1 unit = 4 years.
Ages: \( 8 \times 4 = 32 \) and \( 6 \times 4 = 24 \).
Question 010Standard pattern
Average age of A and B is 30. B and C is 32. C and A is 34. Age of C?
36 years
33 years
34 years
35 years
Correct answer: a) 36 years
Solution
\( A+B = 60, B+C = 64, C+A = 68 \).
Sum: \( 2(A+B+C) = 192 \implies A+B+C = 96 \).
C = \( 96 - 60 = 36 \).
4. Strategy errors to avoid
Error 01Difference neglect: Forgetting that the age gap between two people never changes over time.
Error 02Direct unit subtraction: Trying to subtract ratio units before balancing the differences.
Error 03Timeline confusion: Accidentally adding years when moving to the past or subtracting for the future.
Error 04Variable overuse: Creating complex X/Y equations when a simple ratio shift solves the problem.
