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

The average age of 4 members of a family is 35 years. Their ages are in the ratio 8:7:1:12. What is the age of the oldest member of the family (in years)?

This question was previously asked in
SSC Selection Post 2021 Question Paper (09-Feb-2022) (Shift-1)
The correct answer is
60

Family Age Ratio Calculation Explained

This problem involves finding the age of the oldest family member using the average age and the ratio of their ages. We need to calculate the total age first and then use the ratio to determine individual ages.

Understanding Average Age

The average age is calculated by dividing the sum of all ages by the number of people. The formula is:

Average Age = \(\frac{\text{Total Age}}{\text{Number of Members}}\)

From this, we can find the Total Age:

Total Age = Average Age \(\times\) Number of Members

Calculating Total Family Age

Given:

  • Number of members = 4
  • Average age = 35 years

Using the formula:

Total Age = \(35 \text{ years} \times 4\)

Total Age = \(140\) years

Breaking Down the Age Ratio

The ages of the 4 family members are in the ratio 8:7:1:12. This means their ages can be represented as multiples of some common factor, let's call it '$x$'.

  • Age 1 = \(8x\)
  • Age 2 = \(7x\)
  • Age 3 = \(1x\)
  • Age 4 = \(12x\)

The sum of the parts in the ratio is:

\(8 + 7 + 1 + 12 = 28\) parts

Determining Member Ages Step-by-Step

The sum of the individual ages must equal the Total Age we calculated.

  1. Set up the equation using the ratio parts and the total age:

    \(8x + 7x + 1x + 12x = 140\)

  2. Combine the terms with '$x$':

    \(28x = 140\)

  3. Solve for '$x$' by dividing the total age by the sum of the ratio parts:

    \(x = \frac{140}{28}\)

    \(x = 5\)

Finding the Oldest Member's Age

To find the age of the oldest member, we look for the largest number in the ratio, which is 12. The oldest member's age is represented by \(12x\).

  • Oldest Member's Age = \(12x\)
  • Substitute the value of '$x$' we found: Age = \(12 \times 5\)
  • Oldest Member's Age = \(60\) years

Therefore, the age of the oldest member of the family is 60 years.

Was this answer helpful?

Similar Questions

  1. Four years ago, the ratio of the ages of A and B was 3: 5. Six years hence, the ratio of the ages of A and B will be 2: 3. What is the sum (in years) of the present ages of A and B?
  2. The ages of A and B are in the ratio 4: 7, respectively. After 8 years, the ratio of their ages will be 2: 3. What is the sum of the ages of A and B (in years)?

  3. The present ages of Ramu and Ravi are in the ratio of 4: 3. After 5 years the ratio of their ages will be 5: 4. Find their present ages, respectively.

  4. Six years ago, the average of the ages of Ravi, his wife and their child was 32 years. Nine years ago, the average of the ages of Ravi's wife and the child was 24 years. Find the present age of Ravi?

Important Questions from Problem on Age

  1. The ratio of present ages of Neelam and Rajni is 6 : 7. After four years, their ages will be in the ratio of 8 : 9. What is the present age of Rajni?

  2. Five years ago the age of the son was one third of that of his mother at that time. If the sum of their present ages is 70 years, then find the present age of the mother.

  3. Jaya is 36 years old and her son Bharat is 11 years old. In how many years will Jaya be twice as Bharat's age?

  4. The ratio of a father's age to his son's age is 3 ∶ 2 The product of the numbers representing their age is 486. The ratio of their ages after 5 years will be:

  5. X said to Y, "At the time of your birth I was twice as old as you are at present." If the present age of X is 42 years, then consider the following statements:

    1. 8 years ago, the age of X was five times the age of Y.

    2. After 14 years, the age of X would be two times the age of Y.

    Which of the above statements is/are correct?

Need Expert Advice?
Upcoming Exams
UPSSSC PET
October 25, 2026
SSC JE
November 02, 2026
SSC CPO
November 20, 2026
SSC CHSL
November 30, 2026
Test Series
SSC Selection Post img
SSC
SSC Selection Post (Graduation) (Phase 12) 2025 Mock Test Series
489 Tests 5 Tests Free
5489 Attempts
4.8(317)
English, Hindi

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