Monika’s father was 38 years of age when she was born while her mother was 36 years old when her brother four years younger to her was born. What is the difference between the ages of her parents?
6 years
This problem involves calculating the age difference between Monika's parents based on their ages when their children were born.
We are given two key pieces of information:
We need to find the difference between the ages of Monika's parents.
Let's denote the current ages:
From the first statement, when Monika was born, her age was 0. Her father's age was 38. This means the father is always 38 years older than Monika. So, we can write the relationship:
$\qquad F = M + 38$
From the third statement, Monika's brother is 4 years younger than Monika. This means Monika is 4 years older than her brother. So, we can write the relationship:
$\qquad B = M - 4$
From the second statement, when Monika's brother was born, his age was 0. His mother's age was 36. This means the mother is always 36 years older than the brother. So, we can write the relationship:
$\qquad Mo = B + 36$
We want to find the difference between the ages of her parents, which is $F - Mo$.
We have the equations:
1. $F = M + 38$
2. $B = M - 4$
3. $Mo = B + 36$
We can substitute the value of $B$ from equation (2) into equation (3):
$\qquad Mo = (M - 4) + 36$
$\qquad Mo = M - 4 + 36$
$\qquad Mo = M + 32$
Now we have the ages of the father and mother in terms of Monika's age $M$:
$\qquad F = M + 38$
$\qquad Mo = M + 32$
To find the difference between their ages, we subtract $Mo$ from $F$:
$\qquad F - Mo = (M + 38) - (M + 32)$
$\qquad F - Mo = M + 38 - M - 32$
$\qquad F - Mo = 38 - 32$
$\qquad F - Mo = 6$
The difference between the ages of Monika's parents is 6 years.
| Relationship | Equation | Explanation |
|---|---|---|
| Father's age vs Monika's age | $F = M + 38$ | Father is 38 years older than Monika. |
| Brother's age vs Monika's age | $B = M - 4$ | Brother is 4 years younger than Monika. |
| Mother's age vs Brother's age | $Mo = B + 36$ | Mother is 36 years older than the brother. |
| Mother's age vs Monika's age (Substitution) | $Mo = (M - 4) + 36 = M + 32$ | Substituting brother's age in terms of Monika's age. |
| Difference between Parents' ages | $(M + 38) - (M + 32)$ | Subtracting Mother's age from Father's age. |
The calculation shows that the difference is a constant value (6 years) and does not depend on the current age of Monika ($M$).
Based on the calculations, the difference between the ages of Monika's father and mother is 6 years.
| Concept | Key Idea | Application in Problem |
|---|---|---|
| Age Relationship | Difference in age between two people remains constant over time. | Father is always 38 years older than Monika. Mother is always 36 years older than brother. |
| Relative Ages | Expressing one person's age in terms of another's. | Brother's age = Monika's age - 4. |
| Substitution | Replacing a variable with its equivalent expression. | Substituting brother's age expression into the mother-brother age equation. |
| Solving for Difference | Subtracting the expressions for the two quantities. | Subtracting the expression for Mother's age from the expression for Father's age. |
Age word problems often require setting up algebraic equations based on the relationships given in the problem. Here are some tips:
In this specific problem, the core idea is that the age difference between any two individuals stays constant. By relating both parents' ages to one of the children's ages (via substitution), we could directly find the difference between the parents' ages without needing to know anyone's exact current age.
Bipul is 16 years younger than Saibal. 12 years hence, Saibal's age will be 1.5 times that of Bipul. Saibal is now_____years old.
Ages of Lalu and Balu are in the ratio of 1 : 2, after 7 years their ages ratio changes to 3 : 5. The elder person age is:
The difference between Charles’ and Shriya’s ages is 6 years. When they married each other 30 years ago, 4 times Cahrle’s age was the same as 5 times the age of Shriya. What is the current sum of their ages?
The difference between Peter and Preeti’s ages is 5 years. When they married each other 35 years ago, 4 times Peter’s age was the same as 5 times the age of Preeti’s. What is the current sum of their ages?
13 years ago, Ram was twice as old as Sunny. Three years from now Sunny’s age will be 3/5 of Ram’s age. What is Ram’s current age?
The ages of X and Y are in the ratio 4 : 7. Three years earlier, the ratio of their ages was 1 : 2. What is the difference between their current ages (Y - X)?
Rathin is now 16 years old while his cousin is 7 years. After how many years will Rathin’s age be 1.5 times that of his cousin?
John is 15 years younger than Jill. 12 years ago, Jill’s age was 1.5 times that of John. Jill is now ______ years old.
The present ages of Kavitha, Rajitha and Haritha are in the ratio of 4 : 7 : 9. Eight years ago, the sum of their ages was 56. Find the present ages (in years).
Jeremy is 26 years younger than his father. Eight years hence his father’s age will be two years less than twice his age. What is Jeremy’s present age (in years)?
In 2002, Meenu's age was one-third of the age of Meera, whereas in 2010, Meenu's age was half the age of Meera. What is Meenu's year of birth?
A watch loses 2 minutes in every 24 while another watch gains 2 minutes, in 24 hours. At a particular instant, the two watches showed an identical time. Which of the following statements is correct if 24- hour clock is
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 ?
5 years ago, my sister's age was 5 times my age. Now it is 3 times only. What is my sister's present age (in years)?
The sum of ages of a father and his son is 45 years. Five years ago, the product of their ages (in yrs.) was 124. The present age of father is :