Question

Five years old .nuri was thrice as old as sonu . ten years later ,nuri will be twice as old assonu . how old are nuri and sonu

Answer 1

let the age of nuri be x and sonu be y.
eq.1 ⇒x-5 = 3(y-5)
x-3y = -10
eq.2 ⇒x+10 = 2(y+10)
x-2y = 10
subtracting eq.1 from eq.2
⇒y=20 years
x = 50 years

Answer 2

Let the present age of Nuri be x years and present age of sonu be y years.

According to given conditions,

5 years ago,

x - 5 = 3(y - 5)

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

10 year later,

x + 10 = 2(y + 10)

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

On subtracting eqn 1 from 2,

(x - 2y) - (x - 3y) = 10 + 10

-2y + 3y = 20

y = 20

On substituting y = 20 in eqn 2,

x = 2 × 20 + 10

x = 50

Hence present age of Nuri is 50 years and present age of Sonu is 20 years