Question

4 years ago meera was 3 times as old as manu.8years later Meera would be twice as old as Manu. How old are they now?​

Answer 1

Step-by-step explanation:

$\bf{\underline{\underline\red{Given:-}}}$

• 4 years ago Meera is 3 times as old as Manu.

• 8 years later Meera would be twice as old as Manu.

$\bf{\underline{\underline\blue{To\:Find:-}}}$

• The present ages of Manu and Meera.

$\bf{\underline{\underline\green{Solution:-}}}$

Let the present age of Meera = x

And present age of Manu be y

4 years ago:-

Age of Meera = (x - 4)

Age of Manu = (y - 4)

Meera is 3 times as old as Manu

→ x - 4 = 3(y - 4)

→ x - 4 = 3y - 12

→ x - 3y = -12 + 4

→ x - 3y = -8.......(i)

8 years later:-

Age of Meera = (x + 8)

Age of Manu = (y + 8)

Meera will be twice as old as Manu

→ x + 8 = 2(y + 8)

→ x + 8 = 2y + 16

→ x - 2y = 16 - 8

→ x - 2y = 8

→ -( x -2y = 8)

→ -x + 2y = -8.......(ii)

Adding equation (i) and (ii)

$\: \: \: \rm \not x - 3y = - 8$

$\rm -\not x + 2y = - 8$

_____________

→ -3y + 2y = -8 - 8

→ -y = -16

→ y = 16

Substituting y = 16 in equation (i)

→ x - 3y = -8

→ x -3(16) = -8

→ x - 48 = -8

→ x = -8 + 48

→ x = 40

Present age of Meera = x = 40 years

Present age of Manu = y = 16 years

Answer 2

Given ,

• 4 years ago , Meera was 3 times as old as Manu

• 8 years later , Meera would be twice as old as Manu

Let , the present ages of Meera and Manu be " x " and " y "

According to the problem ,

x - 4 = 3(y - 4)

x - 4 = 3y -12

x - 3y = -8 --- (i)

and

x + 8 = 2(y + 8)

x + 8 = 2y + 16

x - 2y = 8 --- (ii)

Subtract eq (i) from eq (ii) , we get

x - 2y - (x - 3y) = 8 - (-8)

-2y + 3y = 16

y = 16

Put y = 16 in eq (ii) , we get

x - 2(16) = 8

x - 32 = 8

x = 40

$\therefore$ The present ages of Meera and Manu are 40 years and 16 years