Question

banu is 20 years older than binu. in 5 years banu will be twice as old as binu. find their present ages

Answer 1

 Answer :         Let Present age of Binu = x   
      Therefore, Present age of Banu = x+20   
 After 5 years,     
   Age of Binu = x+5       
  Age of Banu = (x+20)+5                    
        = x+25According to question ,   
           x+25 = 2 (x+5)         
    x+25 = 2x + 10               
 25 = 2x+10 - x             
   25 = x+10             
   25 - 10 =x             
   15 = x         
      or x= 15

Hence Present age of Binu = 15 years 
  and Present age of BAnu = x+20                                   
        = 15 + 20                                         
   =35 Years !!

Answer 2

Let the present age of Binu be x
Then the present age of Banu is 20 + x.
Age of Banu after five years = 25 + x
Age of Binu after five years = 5 + x
After five years, 25 + x = 2 (5 + x) 
                       = 25 + x = 10 + 2x
                          25 - 10 = 2x - x
                            15 = x
Therefore Binu's age is 15 years and Banu's age is 35 years.