Question

the ratio of the present age of father to that son is 7:2 after 10 years their ages will be in the ratio of 9:4 the present age of father is. a) 35 years. B) 40 years. c) 30 years. d) 25 years. With explanation
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Answer 1

Step-by-step explanation:

let x

According to question

7x is father's age and 2x is son's age

7x + 10 + 2x + 10 = 9x + 4x

9x + 20 = 13x

20 = 13x - 9x

20 = 4x

x = 20/4

x = 5

father's age = 7x

= 7 * 5

= 35 years

Answer 2

Given

• ratio of the present age of father to that son = 7 : 2

• ratio of the age of father to that son after 10 years = 9 : 4

To Find

• present age of father

Solution :

Let, the multiple of ratio be x

ratio of the age of father to that son after 10 years = 9:4

⇒ 7x + 10 : 2x + 10 = 9 : 4

⇒ 28x + 40 = 18x + 90

⇒ 28x - 18x = 90 - 40

⇒ 10x = 50

⇒ x = 50/10

⇒ x = 5

Present age of father = 7x

➸ Present age of father = 7 × 5

➸ Present age of father = 35

★ Present age of father is 35