Question

Q15: Five years ago, Anu was thrice as old as Sonu. After ten years, Anu will be twice as old as Sonu. How old are Anu and Sonu?

Answer 1

Answer:

Sonu age = 25 years

Anu age = 5 years

Step-by-step explanation:

Let the age of Sonu before 5 years = x

Let the age of Anu before 5 years = 3x

ACCORDING TO THE QUESTION

After 10 years

3x + 10 = (x + 10) * 2

3x + 10 = 2x + 20

3x - 2x = 20 - 10

x = 10

3x = 3*10

3x = 30

THESE ARE THE AGES AFTER 5 YEARS

SO TO FIND PRESENT AGE SUBTRACT AHE AGES FROM 5

Age of Sonu = 10 - 5

                     = 5 years

Age of Anu   = 30 - 5

                     = 25 years

Answer 2

EXPLANATION.

• GIVEN

Five years ago, Anu was thrice as old as sonu.

After 10 years, Anu will be twice as old as sonu.

To find how old are Anu and Sonu ?

According to the question,

Let the present age of Anu = x years.

Let the present age of Sonu = y years.

After 5 years ago,

Anu age will be = x - 5 years.

Sonu age will be = y - 5 years.

Anu was thrice as old as Sonu,

=> x - 5 = 3( y - 5 )

=> x - 5 = 3y - 15

=> x - 3y = -10 ......(1)

After 10 years later the age will be,

Age of Anu = x + 10 years.

Age of Sonu = y + 10 years.

Anu will be twice as old as sonu,

=> x + 10 = 2 ( y + 10 )

=> x + 10 = 2y + 20

=> x - 2y = 10 ....... (2)

From equation (1) and (2) we get,

1. multiply equation (1) by 2
2. multiply equation (2) by 3

we get,

=> 2x - 6y = -20

=> 3x - 6y = 30

we get,

=> -x = -50

=> x = 50

put the value of x = 50 in equation (1)

we get,

=> 50 - 3y = -10

=> -3y = -60

=> y = 20

Therefore,

Age of Anu = 50 years.

Age of sonu = 20 years.