Five years ago nuri was thrice as old as Sonu.Ten years later,Nuri will be twice as old as sonu.How old are Nuri and Sonu now

Step 1: identify the two variables 

             Nuri = x

            Sonu = y

Step 2 : formulate the equations

Five years ago nuri was thrice as old as Sonu

 

                         x - 5 = 3(y - 5)

                         x - 5 = 3y - 15

                         x - 3y = -15 + 5

Thus, Equation 1 is          

                         x - 3y = - 10

Ten years later,Nuri will be twice as old as sonu

                        x + 10 = 2(y + 10)

                        x + 10 = 2y + 20

                        x - 2y = -10 + 20

Thus, Equation 2 is

                       x - 2y = 10

Step 3 : Eleminate one variable

Subtracting both Equations

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

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

                                     y = 20

Step 4: Substitute the value of y in Equation 1

                       x - 3y = - 10

                       x - 3(20) = - 10

                       x - 60 = - 10

                       x = - 10 + 60 

                       x = 50

Therefore Nuri is 50 years old now and Sonu is 20 years old