Question

The present age of mother is 40 years and that of her daughter is 10 years.
(i) Find the ratio of present age of the mother to the present age of her daughter.
(ii) Find the ratio of age of the mother to the age of daughter, when daughter was 8 years old.
(iii) Find the ratio of age of mother after 10 years to the age of daughter after 10 years.

Answer 1

Answer: Let present age of daughter be x.

So 5 years ago her age =x−5

Her mother's age is 7(x−5)

Including 5 years from past to present and then to future =10

So 7x−35+10=3(x−5+10)

7x−25=3x+15

4x=40

x=10

so daughters age=10

mother's age=4×10=40.

Step-by-step explanation:

Answer 2

Step-by-step explanation:

Ratio of present ages of mother and daughter = 5 : 1

Ratio of ages of mother and daughter after 6 years = 3 : 1

Concept Used:

The difference between ages of two persons at any time is constant.

Calculation:

Let the present ages of Mother and Daughter be 5x and x

After 6 years their ages will be 5x + 6 and x + 6

According to the question-

(5x + 6)/(x + 6) = 3/1

⇒ 5x + 6 = 3x + 18

⇒ x = 6

∴ The present age of daughter is 6 years.