Peter and Paul are two friends. The 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?
a) 8 b) 20 c) 16 d) 15

• let us assume peter's present age is x and paul,s y=35-x.
  difference of their ages is x-(35-x)=2x-35
  peter's age was 35-x when he was paul's age
  and paul was of 35-x-(2x-35)=70-3x
  peter's present age is 2*(70-3x) which is equals to x
  so, x=140-6x then x=20
  thanx.
  
• 12 years agoHelpfull: Yes(11) No(2)
• Let us assume peter's age is x and paul's is 35-x
  peter's age was as much as paul'a present age 2x-35 yrs before.
  so at that time paul's age was 35-x-(2x-35)=70-3x
  so right now peter's age is 2*(70-3x)=x
  ->140-6x=x
  ->x=20
• 12 years agoHelpfull: Yes(4) No(1)
• peter age=x,paul age=y,x+y=35
  given,x=2(x-2(x-y))
  x=2x-4x+4y
  x=4y/3,
  sub in to x+y=35,
  4y/3+y=35
  y=15
  so,x=20
• 12 years agoHelpfull: Yes(2) No(1)
• peter age=x,paul age=y,x+y=35
  given,x=2(x-2(x-y))
  x=2x-4x+4y
  x=4y/3,
  sub in to x+y=35,
  4y/3+y=35
  y=15
  so,x=20
• 12 years agoHelpfull: Yes(1) No(1)