All Exams Test series for 1 year @ ₹349 only
Question

Ram’s father is thrice as old as Ram is. 4 years ago, the age of Ram’s father was 4 times his age. What is Ram’s current age?

This question was previously asked in
RRB ALP 2018 CBT 2 Fitter Question Paper (21-Jan-2019) (Shift 3)
The correct answer is

12 years

Understanding the Ram's Age Problem

This question asks us to find Ram's current age based on given relationships between his age and his father's age at two different points in time: currently and 4 years ago. These types of problems are classic age word problems that can be solved using algebraic equations.

Setting Up the Age Problem

To solve this age problem, we can use variables to represent the unknown ages. Let's define:

  • Let Ram's current age be \(R\) years.
  • Let Ram's father's current age be \(F\) years.

Formulating Equations from the Problem Statement

The problem gives us two key pieces of information, which we can translate into two equations:

  1. "Ram’s father is thrice as old as Ram is." This describes their current ages.
    In terms of our variables, this means:
    \(F = 3R\)
  2. "4 years ago, the age of Ram’s father was 4 times his age." This describes their ages in the past.
    4 years ago, Ram's age was \(R - 4\) years.
    4 years ago, Ram's father's age was \(F - 4\) years.
    The relationship given is that the father's age 4 years ago was 4 times Ram's age 4 years ago:
    \(F - 4 = 4 \times (R - 4)\)

Now we have a system of two linear equations with two variables:

  • Equation 1: \(F = 3R\)
  • Equation 2: \(F - 4 = 4(R - 4)\)

Solving the System of Equations to Find Ram's Current Age

We can use substitution to solve this system. We already have an expression for \(F\) in terms of \(R\) from Equation 1. We can substitute \(3R\) for \(F\) into Equation 2.

  1. Substitute \(F = 3R\) into Equation 2:
    \( (3R) - 4 = 4(R - 4) \)
  2. Now, simplify and solve for \(R\):
    Distribute the 4 on the right side of the equation:
    \( 3R - 4 = 4R - 16 \)
    Move the terms involving \(R\) to one side and the constant terms to the other side. Subtract \(3R\) from both sides:
    \( -4 = 4R - 3R - 16 \)
    \( -4 = R - 16 \)
    Add 16 to both sides to isolate \(R\):
    \( -4 + 16 = R \)
    \( 12 = R \)

So, Ram's current age is 12 years.

We can check this answer using the original equations:

  • If Ram's current age (\(R\)) is 12, his father's current age (\(F\)) should be \(3 \times 12 = 36\) years. (Checks Equation 1: \(36 = 3 \times 12\))
  • 4 years ago, Ram's age was \(12 - 4 = 8\) years.
  • 4 years ago, his father's age was \(36 - 4 = 32\) years.
  • Is the father's age 4 years ago (32) 4 times Ram's age 4 years ago (8)?
    \(32 = 4 \times 8\)
    \(32 = 32\) (Checks Equation 2)

Both conditions are satisfied, confirming that Ram's current age is 12 years.

Conclusion: Ram's Current Age

Based on our calculations from the given information, Ram's current age is 12 years.

Summary of Ages
Person Current Age Age 4 Years Ago
Ram \(R = 12\) \(R - 4 = 12 - 4 = 8\)
Father \(F = 3R = 3 \times 12 = 36\) \(F - 4 = 36 - 4 = 32\)

Revision Table: Key Concepts for Age Problems

Age Problem Solving Steps
Step Description Example (from this problem)
1 Assign variables to unknown present ages. Ram's current age = \(R\), Father's current age = \(F\).
2 Express ages at different times (past/future) using these variables. Ram's age 4 years ago = \(R-4\), Father's age 4 years ago = \(F-4\).
3 Translate the relationships given in the problem into algebraic equations. \(F = 3R\), \(F - 4 = 4(R - 4)\).
4 Solve the system of equations. Substitution or elimination methods can be used. Substitute \(F = 3R\) into the second equation: \(3R - 4 = 4R - 16 \implies R = 12\).
5 Check your answer against the original problem conditions. If \(R=12\), \(F=36\). 4 years ago: Ram=8, Father=32. \(32 = 4 \times 8\). Correct.

Additional Information: Solving Age Word Problems

Age word problems are a common application of linear equations. They often involve relationships between the ages of two or more people at different points in time. The key to solving them is careful translation of the word phrases into mathematical expressions and equations.

  • Phrases like "twice as old as" or "thrice as old as" indicate multiplication.
  • Phrases like "X years ago" require subtracting X from the current age.
  • Phrases like "in X years" or "after X years" require adding X to the current age.
  • The relationships given in the problem usually provide the equations needed to solve for the variables.

Always define your variables clearly and state what they represent (usually current ages). This helps avoid confusion when setting up the equations and interpreting the final answer.

Was this answer helpful?

Similar Questions

  1. There are 361 saplings of Mango and Neem in a garden. The ratio of the number of Mango saplings to that of Neem saplings is 8 : 11. How many Neem saplings are there in the garden?

  2. In a bag containing red, green and pink tokens, the ratio of red to green tokens was 5 : 12 while the ratio of pink to red tokens was 7 : 15. What was the ratio of green to pink tokens?

  3. There are red(A), yellow(B) and green(C) tokens in a bag. A : B ∷ 3 : 8, B : C ∷ 6 : 13, Find the value of A : B : C.

  4. The ratio of sand to gravel in a mixture is 3 : 4, while that between gravel and cement is 6 : 7. What is the ratio of sand to cement in the mixture?

  5. The ratio of sand to gravel in a mixture is 7 : 8 while that between gravel and cement is 6 : 7. What is the ratio of sand to cement in the mixture?

  6. Some one rupee, 50 paisa and 25 paisa coins make up rupees 93.75  and their numbers are in the proportion of  3 ∶ 4  ∶  5 . Find the number of each type of coins?
  7. When a wire 25.2 m long is divided in the ratio 11 ∶ 25 the length of the longer piece is:

  8. In a class consisting of boys and girls, there are 45 students. If three fifth of the students are boys, find the number of boys in the class.

  9. The ratio of the heights of Nani and Leelu is 4 : 3. If Leelu is 1.2 m tall, then what is the height of Nani?

  10. Vishnu spends Rs. 5000 in buying 12 tables and some chairs. The cost of one table is Rs. 50 and that of one chair is Rs. 40. What is the ratio of the numbers of the chairs to the number of tables purchased?


Important Questions from Simple Ratios

  1. The ratio of two numbers is 9 : 5. If 8 is added to the larger number and 4 is subtracted from the smaller number, the greater number becomes twice the smaller number. The larger number is:

  2. Divide 500 into two parts such that the ratio of one to the other are in 5 : 3?

  3. The ratio of the number of men and women in a company is 5 : 4. If the number of men and women increase by 16% and 15%, respectively, then what will be the new ratio of men and women ?

  4. The monthly salaries of an officer and a clerk are in the ratio 11 : 4. If the monthly salary of the officer increases by ₹7,000 and that of the clerk by ₹3,000, then the ratio becomes 19 : 7. What was the initial salary (in ₹) of the officer? 

  5. If X : Y = 7 : 5 and Y : Z = 7 : 11, then what is the ratio of X : Y : Z?

Need Expert Advice?
Upcoming Exams
RRB NTPC
September 27, 2026
Test Series
RRB ALP img
Railways
RRB ALP 2026 Mock Test series
1035 Tests 1 Tests Free
889 Attempts
4.3(235)
English, Hindi
More Questions from RRB ALP

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App