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Question

A father is four times as old as his son today. After 24 years, the ratio of ages of son and father will be 1 : 3. Find the present age of the son

The correct answer is

48

Solving Father Son Age Ratio Problem

This problem involves setting up equations based on the given information about the ages of a father and his son at different points in time.

Setting up the Equations

Let's use variables to represent the ages:

  • Let the present age of the son be \(S\) years.
  • Let the present age of the father be \(F\) years.

According to the first statement, the father is four times as old as his son today. We can write this as an equation:

\(F = 4S\)

Next, we consider the ages after 24 years:

  • Son's age after 24 years will be \(S + 24\) years.
  • Father's age after 24 years will be \(F + 24\) years.

The problem states that after 24 years, the ratio of the ages of the son and father will be 1 : 3. This gives us another equation:

\(\frac{S + 24}{F + 24} = \frac{1}{3}\)

Solving the Equations

Now we have a system of two equations:

  1. \(F = 4S\)
  2. \(\frac{S + 24}{F + 24} = \frac{1}{3}\)

We can substitute the first equation into the second equation to eliminate \(F\). Replace \(F\) with \(4S\) in the second equation:

\(\frac{S + 24}{4S + 24} = \frac{1}{3}\)

Now, we solve this equation for \(S\). We can cross-multiply:

\(3 \times (S + 24) = 1 \times (4S + 24)\)

Distribute the numbers:

\(3S + 72 = 4S + 24\)

To isolate \(S\), subtract \(3S\) from both sides of the equation:

\(72 = 4S - 3S + 24\)

\(72 = S + 24\)

Now, subtract 24 from both sides to find the value of \(S\):

\(72 - 24 = S\)

\(S = 48\)

So, the present age of the son is 48 years.

Verification

Let's check if this answer fits the conditions:

  • Son's present age = 48 years.
  • Father's present age = \(4 \times 48 = 192\) years. (Father is four times as old as the son)
  • After 24 years, son's age = \(48 + 24 = 72\) years.
  • After 24 years, father's age = \(192 + 24 = 216\) years.
  • Ratio of son's age to father's age after 24 years = \(\frac{72}{216}\).

Let's simplify the ratio \(\frac{72}{216}\):

\(\frac{72}{216} = \frac{72 \div 72}{216 \div 72} = \frac{1}{3}\)

The ratio is 1:3, which matches the condition given in the problem. Therefore, the present age of the son is 48 years.

The final answer is \(48\).

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Important Questions from Age

  1. 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?

  2. 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

  3. 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 ?

  4. 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)?

  5. 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 :

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