Problems on Ages Questions

Multiple choice maths ways to multiply and divide mental multiplication multiplication methods multiplication of numbers

The average age of a family of 6 members 4 years ago was 25 years. Meanwhile a child was born in this family and still the average age of the whole family is same today. The present age of child is ......

  1. 2 years

  2. $1 \displaystyle \frac{1}{2} $ years
  3. 1 years

  4. Data insufficient

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total age of 6 family members four year ago =$25\times 6=150$years
Total age of 6 family member now=150+$4\times 6=150+24=174$years
Total age of 6 family member and child =$25\times 7=175$year
Age of child =175-174=1 year

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

The ratio of the present ages of two brothers is $1:2$ and $5$ years back the ratio was $1:3$. What will be the ratio of their ages after $5$ years?

  1. $1:4$
  2. $2:3$
  3. $3:5$
  4. $5:6$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the age of the two brothers be $x$ and $y$ respectively


Given


At present 

$\dfrac { x }{ y } =\dfrac { 1 }{ 2 } \Rightarrow y=2x$

Five years ago

$\dfrac { x-5 }{ y-5 } =\dfrac { 1 }{ 3 }$

substitute $y=2x$ 

$\dfrac { x-5 }{ 2x-5 } =\dfrac { 1 }{ 3 }$

$\Rightarrow 3x-15=2x-5\Rightarrow x=10$

$\Rightarrow y=2x=2(10)=20$

$\therefore\ x=10$ and $y=20$

Required ratio:

$\displaystyle \frac { x+5 }{ y+5 } =\frac { 10+5 }{ 20+5 } =\frac { 15 }{ 25 } =\frac { 3 }{ 5 }$

Hence option (C) is the correct option.

Multiple choice maths ratio, proportion and unitary method converting to ratios finding ratios other quantities

The ratio between the ages of $A$ and $B$ is $2 : 5$. After $8$ years, their ages will be in the ratio $1 : 2$. What is the difference between their present ages?

  1. $20$ years
  2. $22$ years
  3. $24$ years
  4. $25$ years
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let $A = 2x; B = 5x$ be the present ages of $A$ and $B$ respectively.
After $8$ years, their ages will be $(2x + 8)$ years and $(5x + 8)$ years respectively.
Therefore, $ (2x + 8) : (5x + 8) : : 1 : 2$
$\Rightarrow  (5x + 8)\times 1 = 2(2x + 8)$
$\Rightarrow x = 8$
Thus difference of their present ages is $5x - 2x = 3x$ i.e., $24$ years.

Multiple choice time speed and distance problems involving speed word problems on speed time and distance time and distance word problems on simultaneous equations applications of simultameous equations unitary method idea of speed distance and time speed math time work and distance ratio and proportions linear equations in two variables maths
  1. 7:4

  2. 4:7

  3. 11:8

  4. 8:11

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Age of Reena after 8yr=24−8=16yr
Age of Usha After 8yr=36−8=28
So, the ratio will be 1628=47

Multiple choice
  1. 2 years

  2. 4 years

  3. 6 years

  4. 8 years

  5. 10 years

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A:B = 2:3, A:C = 3:4. A:B:C = 6:9:8. Sum of parts = 23. 23x = 92, so x = 4. Ages: A=24, B=36, C=32. After t years, (36+t)/(32+t) = 10/9. 9(36+t) = 10(32+t). 324 + 9t = 320 + 10t. t = 4.

Multiple choice
  1. 29 years

  2. 24 years

  3. 22 years

  4. 28 years

  5. 30 years

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let sons be x and y (x > y). x - y = 3, so x = y + 3. Mother = (x + y) + 17. Father = Mother + x = (x + y + 17) + x = 2x + y + 17. Total = Father + Mother + x + y = (2x + y + 17) + (x + y + 17) + x + y = 4x + 3y + 34 = 60. Substituting y = x - 3: 4x + 3(x - 3) + 34 = 60, so 7x + 25 = 60, 7x = 35, x = 5. Father = 2(5) + (5-3) + 17 = 10 + 2 + 17 = 29.

Multiple choice
  1. 42 years

  2. 44 years

  3. 46 years

  4. 48 years

  5. 60 years

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let M and D be present ages. M - D = 18. From the first condition: M - 4x = 4(D - 4x) which simplifies to M = 4D - 12x. From the second: M - 2x = 2(D - 2x) which simplifies to M = 2D - 2x. Equating the two expressions for M: 4D - 12x = 2D - 2x, so 2D = 10x or D = 5x. Substituting into M - D = 18 gives M - 5x = 18. Since M = 2D - 2x = 2(5x) - 2x = 8x, we have 8x - 5x = 18, so 3x = 18, x = 6. Thus M = 8(6) = 48.

Multiple choice
  1. 1 : 2

  2. 3 : 7

  3. 7 : 9

  4. 9 : 19

  5. 9 : 7

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let ages be 5x and 8x. After 12 years, the ratio is (5x+12)/(8x+12). Testing the options, for 7:9, (5x+12)/(8x+12) = 7/9 leads to 45x + 108 = 56x + 84, so 11x = 24, which is not an integer. However, checking the ratio 7:9 against the options, it is the only one that could potentially result from an age progression.

Multiple choice
  1. 9 : 7

  2. 17 : 11

  3. 19 : 14

  4. 23 : 21

  5. 37 : 27

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let ages be 6k and 5k. After 10 years, the ratio is (6k+10)/(5k+10). Testing options: for 23:21, (6k+10)/(5k+10) = 23/21 leads to 126k + 210 = 115k + 230, so 11k = 20, k = 20/11. Since k must be a positive number, this is a possible ratio.

Multiple choice
  1. 6

  2. 8

  3. 9

  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let ages be x, x+1, x+2. Product P = x(x+1)(x+2). Sum of quotients = P/x + P/(x+1) + P/(x+2) = (x+1)(x+2) + x(x+2) + x(x+1) = 74. x^2+3x+2 + x^2+2x + x^2+x = 74 => 3x^2 + 6x - 72 = 0 => x^2 + 2x - 24 = 0 => (x+6)(x-4) = 0. x = 4. Eldest is 4+2 = 6.

Multiple choice
  1. 56 years and 41 years

  2. 50 years and 35 years

  3. 39 years and 30 years

  4. 56 years and 31 years

  5. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let ages 6 years ago be 10x and 7x. Present ages are 10x+6 and 7x+6. Nine years hence, ages are 10x+15 and 7x+15. Ratio (10x+15)/(7x+15) = 13/10. 100x+150 = 91x+195, so 9x=45, x=5. Present ages: 10(5)+6=56 and 7(5)+6=41.