Question

if the sister is three time older than her brother. five years earlier she was five times as old as her brother . what is the present age of the sister ?
a.25year
b.35year
c.30year
d.40year

Answer 1

Let the present age of brother be a

Sister's present age = 3a

5 years ago

Sister's age = (3a - 5) years

Brother's age = (a - 5) years

According to question


5 (a - 5) = 3a - 5

=> 5a - 25 = 3a - 5

=> 5a - 3a = 25 - 5

=> 2a = 20

=> a = 10

Sister's present age = 3a = 3 × 10 = 30 years

Answer 2

Heya......^_^

Here's ur ans. ⬇

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↪ Let the age of sister be x years and that of his brother y years

According to the question

x = 3y ... 1st equation

(x - 5) =5(y-5) .. 2nd equation

Substituting the value of x in 2nd equation

3y - 5 = 5y - 25

3y - 5y = -25 + 5

-2y = -20

y = 10

Therefore ,

x = 3× 10 = 30

Hence , age of his sister is 30 years .

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✌Hope it helps