Quantitative Aptitude

Problems on Ages

346 Questions

Problems on Ages involve calculating current, past, or future ages using ratios, averages, and simple equations. These questions are a regular feature in the arithmetic section of most competitive exams. Practicing these problems helps improve calculation speed and accuracy for time management during tests.

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Problems on Ages Questions

Multiple choice general knowledge math & puzzles

After replacing an old man by a new man,average of five members team of a club is same as it was 3 years ago. What is the difference between the age of the replaced one and the new member:

  1. 4

  2. 10

  3. 8

  4. 15
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For 5 team members, if 4 aged 3 years (total +12), the new member must be 15 years younger than the old member to keep the average the same as 3 years ago (compensating for all 5 members aging 3 years = 15 years total).

Multiple choice general knowledge math & puzzles

The sum of ages of 5 children born at the intervals of 3 years each is 50 years. What is the age of the youngest child?

  1. 6 Years.

  2. 4 Years.

  3. 3 Years.

  4. 5 Years.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the youngest child's age be x. The ages are x, x+3, x+6, x+9, x+12. Sum = 5x + 30 = 50, so 5x = 20 and x = 4. The arithmetic progression with common difference 3 is the key structure. Checking: 4 + 7 + 10 + 13 + 16 = 50.

Multiple choice general knowledge math & puzzles

The age of the father 3 years ago was 7 times the age of his son. At present the father's age is 5 times that of his son. What are the present ages of the father and the son?

  1. 40 & 8

  2. 50 & 10

  3. 45 & 9

  4. 35 & 7
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the father's age be F and son's age be S. 3 years ago: F-3 = 7(S-3), so F = 7S - 18. Present: F = 5S. Equating: 5S = 7S - 18, giving 2S = 18, so S = 9. Then F = 5×9 = 45. Checking: 3 years ago, father was 42 and son was 6, and 42 = 7×6. Option C (45 & 9) is correct.

Multiple choice general knowledge math & puzzles

The avg. age of 30 boys of a class is 14 years. When the age of the class teacher is included, the average becomes 15 years. Find the age of class teacher?

  1. 40

  2. 39

  3. 45

  4. 42
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total age of 30 boys = 30 × 14 = 420 years. When teacher is included, 31 people have average 15, so total = 31 × 15 = 465 years. Teacher's age = 465 - 420 = 45 years. This is a standard average problem where you work backwards from totals.

Multiple choice general knowledge math & puzzles

Diophantus's youth lasted 1/6 of his life. He had his first beard in the next 1/12 of his life. At the end of the following 1/7 of his life Diophantus got married. Five years from then his son was born. His son lived exactly 1/2 of Diophantus's life. Diophantus died 4 years after the death of his son. How long did Diophantus live?

  1. 75

  2. 76

  3. 80

  4. 84
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Set Diophantus's total life as x years. Youth: x/6. First beard: x/12. Marriage: x/7. Son born: 5 years later. Son's life: x/2. Diophantus lived 4 more years after son's death. So x = x/6 + x/12 + x/7 + 5 + x/2 + 4. Solving: x = x(1/6+1/12+1/7+1/2) + 9 = x(14/84+7/84+12/84+42/84) + 9 = x(75/84) + 9. Then x - 75x/84 = 9, so 9x/84 = 9, giving x = 84.

Multiple choice general knowledge math & puzzles

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

  1. 22

  2. 40 years

  3. 43years

  4. 36years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

4 years ago, total age was 10 × (avg - 4) = 10avg - 40. Now total age is 10avg. The difference of 40 years equals (old member's age then) - (new member's age now). Since old aged 4 years, their current age would be 4 years more. Therefore new member is 40 years younger than current old member would be.

Multiple choice general knowledge math & puzzles

A boy is 4 years old and his sister is three times as old as he is. When the boy is 12, how old will his sister be?

  1. 18

  2. 16

  3. 20

  4. 21
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To solve this question, the user needs to know basic arithmetic, the concept of multiplication and subtraction.

Let the sister's age be x.

Given, the boy is 4 years old and his sister is three times as old as he is. Therefore:

x = 3(4) = 12

So, the sister's current age is 12 years.

When the boy is 12 years old, it means that 8 years have passed since he was 4 years old. At that time, his sister's age would be:

x + 8 = 12 + 8 = 20

Therefore, the correct answer is:

The Answer is: C. 20.

Multiple choice general knowledge math & puzzles

A father is three times as old as his son. After fifteen years the father will be twice as old as his son's age at that time. What is the present age of the father?

  1. 36

  2. 42

  3. 45

  4. 48
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let son be x, father 3x. In 15 years: 3x + 15 = 2(x + 15). Solving gives x = 15. Father's present age is 3x = 45. Distractors like 36 or 42 do not satisfy the 'twice as old' condition after 15 years.

Multiple choice general knowledge math & puzzles

Father is aged three times more than his son Johnny. After 8 years, he would be two and a half times of Johnny's age. After further 8 years, how many times would he be of Johnny's age?

  1. 2 times

  2. 2.5 times

  3. 2.75 times

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let Johnny's age = x. Father = 4x (three times more means four times as much). After 8 years: 4x + 8 = 2.5(x + 8). Solving: 4x + 8 = 2.5x + 20, so 1.5x = 12, x = 8. After 16 more years (total 24 years from now), Johnny = 32, Father = 64. Ratio = 64/32 = 2 times.

Multiple choice general knowledge math & puzzles

Man Wrinkle spent one-fourth of his life as a boy, one-eighth as a youth, and one-half as an active man. If Man Wrinkle spent 12 years as an old man, then how many years did he spend as an active man?

  1. 64

  2. 48

  3. 36

  4. 128
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let total life = x years. As boy: x/4, as youth: x/8, as active man: x/2, as old man: 12 years. Total: x/4 + x/8 + x/2 + 12 = x. Converting to eighths: 2x/8 + x/8 + 4x/8 + 12 = x, so 7x/8 + 12 = x, which means 12 = x/8, so x = 96 years. Active man period = x/2 = 48 years.