After five years, Mayank's age will be 3/5th of his father's age. Five

1.	After five years, Mayank's age will be 3/5th of his father's age. Five years ago their age ratio was 2 : 5. Find the present age of Mayank.A. 17B. 13C. 19D. 151. D2. C3. B4. A
Answer» Correct Answer - Option 3 : B Given: Five years ago the ratio of the age of Mayank to his father was 2 : 5. After 5 years their ages will be in the ratio of 2 : 5. Calculation: Let the present age of Mayank be M years and his father’s be F years As given after 5 years their ages will be in the ratio of 3:5 ⇒ (M + 5)/(F + 5) = 3:5 ⇒ 5(M + 5) = 3(F + 5) ⇒ 5M + 25 = 3F + 15 ⇒ 3F – 5M = 10 ----(1) As given 5 years before their ages are in the ratio of 2:5 ⇒ (M – 5)/(F – 5) = 2:5 ⇒ 5(M – 5) = 2(F – 5) ⇒ 5M – 25 = 2F – 10 ⇒ 5M – 2F = 15 ----(2) From (1) & (2) ⇒ 3F – 5M = 10 (Add them) ⇒ 5M – 2F = 15 ⇒ F = 25 years, By putting F in any of the above equations we get, M = 13 years ∴ The present age of Mayank is 13 years

After five years, Mayank's age will be 3/5th of his father's age. Five years ago their age ratio was 2 : 5. Find the present age of Mayank.A. 17B. 13C. 19D. 151. D2. C3. B4. A

Answer» Correct Answer - Option 3 : B

Given:

Five years ago the ratio of the age of Mayank to his father was 2 : 5.

After 5 years their ages will be in the ratio of 2 : 5.

Calculation:

Let the present age of Mayank be M years and his father’s be F years

As given after 5 years their ages will be in the ratio of 3:5

⇒ (M + 5)/(F + 5) = 3:5

⇒ 5(M + 5) = 3(F + 5)

⇒ 5M + 25 = 3F + 15

⇒ 3F – 5M = 10 ----(1)

As given 5 years before their ages are in the ratio of 2:5

⇒ (M – 5)/(F – 5) = 2:5

⇒ 5(M – 5) = 2(F – 5)

⇒ 5M – 25 = 2F – 10

⇒ 5M – 2F = 15 ----(2)

From (1) & (2)

⇒ 3F – 5M = 10 (Add them)

⇒ 5M – 2F = 15

⇒ F = 25 years, By putting F in any of the above equations we get, M = 13 years

∴ The present age of Mayank is 13 years

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