there are two friends peter and paul.Peter age is twice as old as paul when peter was as old as paul is now. sum of the present age of peter and paul is 35. What is the present age of the peter is?

• let pauls age be 'a' and peters be 'e'
  e+a=35 (given)
  e=35-a ------eq1
  when peter was as old as paul that is when peter's age was 'a' i.e e-(e-a) [for example if e was 9 and a was 5, e-a is 4,9-4=5 so e-(e-a)]
  pauls age was a-(e-a) =2a-e
  now peters age is e=2(2a-e)
  e=4a-2e
  3e=4a
  3(35-a)=4a
  105-3a=4a
  a=15
  hence e=20
  so peter age is 20 years.
• 12 years agoHelpfull: Yes(12) No(5)
• Solve by hit and trial method. The present ages of Peter and Paul are 21 and 14. (21+14=35).
  Before 7 years, Peter was 14 years old and Paul was 7 years old i.e. Peter's age was double of that of Paul.
  Hence Peter's current age is 21 years.
• 12 years agoHelpfull: Yes(11) No(7)
• Let the present age of peter is = x , and of paul is y.
  x+y = 35 ... (1)
  The time when peter's is y was = (x-y)
  So this ques. is taking about (x-y) year before.
  So . y = 2(y-(x-y))
  y = 4y - 2x
  2x -3y = 0 .. (2)
  x = 21 and y = 14.
  
  
• 12 years agoHelpfull: Yes(6) No(2)
• peter+paul=35
  peter's age-(peter's age-paul age)=2(paul-(peter-paul)
  paul =2paul-2peter+2paul
  2peter=3paul
  2peter=3(35-peter)
  5peter=105
  peter=21
  paul=14
  u can check the condition when peter was of paul' age i.e =14
  then paul's age was =7 ..so peter is twice of paul's age!!
• 12 years agoHelpfull: Yes(4) No(2)
• 21 is correct... 20is not if it is 20 then paul's age 15 20+15=35, so when peter's age was 15 paul's age was 10 and 10*2#15.. 1st condition violates............
  
• 12 years agoHelpfull: Yes(3) No(0)