peter and paul are two friends.sum of their ages is 35 years.peter is twice as old as paul was when peter was as old as paul is now.what is the present age of peter ?

• Ans:21 years;
  Let Paul' present age is x;
  AS per the qsn:
  when Peter is x yrs old then at that time Paul is x/2 yrs old;
  so present ages:Paul is x(x/2 + x/2) and peter is x + x/2;
  
  According to the qsn: x + (x + x/2)=35;
  5x/2=35;
  so x=14 and x + x/2 is 21
  Peter's present age is 21 years old
• 11 years agoHelpfull: Yes(7) No(8)
• ans is 21
  
  assume peter and paul x and y
  now peter was as old as paul was in x-y years back
  ie x-(x-y)= 2(y-(x-y))
  y = 2(2y-x)
  y= 4y - 2x
  3y = 2x
  y = 2x/3
  noe putting this value in eqn x+y = 35
  we get x= 21
  ie peter' present age is 21
• 11 years agoHelpfull: Yes(6) No(2)
• let peter's present age= X
  paul's present age =Y
  as per question, X+ Y=35
  now.. peter is twice as old as 'paul was, when peter was as old as paul is now' (stated). i.e., read from last => paul is now = Y ; and say 'a' years before, Peter's age (i.e., (X -a)) was equal to the present age of Paul => X-a = Y, and 'a' years ago, peter's age must be ( present age of Peter - a )= ( Y - a) = ( X - 2a ) ; As per the 2nd line of the question, X= 2* ( X- 2a)=> X= 4a; Y =3a
  Now use the equation X+ Y =35 => 4a+3a=7a=35 => a= 5
  therefore, X = 4a =20 (ans)
• 11 years agoHelpfull: Yes(4) No(1)
• THERE IS A SILLY MISTAKE IN MY PREVIOUS SOLUTION.. READ IT.. HOPE IT IS CLARLY EXPLAINED FOR U:
  let peter's present age= X
  paul's present age =Y
  as per question, X+ Y=35
  now.. peter is twice as old as 'paul was, when peter was as old as paul is now' (stated). i.e., read from last => paul is now = Y ; and say 'a' years before, Peter's age (i.e., (X -a)) was equal to the present age of Paul => X-a = Y, and 'a' years ago, paul's age must be ( present age of Paul - a )= ( Y - a) = ( X - 2a ) ; As per the 2nd line of the question, X= 2* ( X- 2a)=> X= 4a; Y =3a
  Now use the equation X+ Y =35 => 4a+3a=7a=35 => a= 5
  therefore, X = 4a =20 (ans)
• 11 years agoHelpfull: Yes(4) No(0)
• assume peter=x paul=y
  given that x+y=35,x=2(2y-a)
  3x=4y
  x=4/3y
  substituting v get x=20,y=15
• 11 years agoHelpfull: Yes(3) No(0)
• Hi sumit... Can you give me clear explanation pls
• 11 years agoHelpfull: Yes(1) No(0)