Most Important Formulas of Problem On Age
PROBLEMS ON AGE
Points to be Remember when Solving Problems on Ages.
- If the present age of a person is ‘x’, then the age after the ‘n’ year will be x + n.
- If the present age of a person is ‘x’, then age ‘n’ years ago will be = x-n.
- If the present age of the person is ‘x’, then ‘n’ times the present age will be = nx⦁
- If the age is mentioned in the ratio A: B, then A: B will be AX and BX.
- If the sum of ages is X and Y and the ratio of their ages in p: q, then you can determine the age of ‘Y’ by the formula below
Age of Y= sum of ages
Age of Y= A
Some of these examples will make it easy to understand problems on ages
1. The ratio of the ages of Ravi and Rohit is 9: 10 respectively. Ten years of age, the ratio of their ages was 4: 5 respectively. What is the present age of Rohit?
A. 15 years
B. 18 years
C. 20 years
D. 22 years.
So, Let Ravi age be 9x years. Then Rohit age = 10x year
∴ Present age of Rohit = (10. 2) = 20 years
2. The age of the father 10 years ago was thrice the age of his son. 10 years hence, the father’s age will be twice that of his son. The ratio of their present ages is
A. 8: 5
B. 7: 3
C. 9: 5
D. 5: 2
Sol. Let Son’s age 10 years ago be x years Then, Father’s age 10- years ago = 3x years
Son’s age Now = (x + 10) years,
Father’s age now = (3x + 10) years (3x + 10) + 10 = 2[(x + 10) + 10] ⇒ 3x + 20 = 2(x + 20) ⇒ 3x + 20 = 2x + 40 ⇒ x = 20
The ratio of present ages of Father and Son
3. The ratio of the present age of a Mother and her Daughter is 7: 1. Four years ago, the ratio of their ages was 19: 1. What will be the Mother’s age four years from now?
A. 46 years
B. 42 years
C. 38 years
D. 36 years.
Let Mother’s age be 7x years. Then Daughter’s age = x years
Mother’s age after 4 years = (7x + 4) = (7 6 + 4) years = 46 years
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