After 10 years A will be twice the age of B before 10 years and now if the difference is 9 years between them then what is the age of B after 10 years.

• A+10=2(B-10) & A-B=9 i.e. A=B+9,
  
  B+19=2B-20 so B=39,
  
  after 10 years B will be 39+10=49. Ans =49
  
• 12 years agoHelpfull: Yes(12) No(1)
• Let the ages of A and B be a and b respectively.
  Then, a + 10 = 2(b - 10) ---------(i)
  also, a - b = 9 --------(ii)
  From both the equations,
  => 9 + b + 10 = 2b - 20.
  => 19 + b = 2b - 20.
  => b = 39
  Hence, the age of B after 10 years will be 39 + 10 = 49.
• 7 years agoHelpfull: Yes(1) No(0)
• B=39
  X AS B'S AGE
  (X+9)+10=2(X-10)
  X=9+10+20
  X=39
• 12 years agoHelpfull: Yes(0) No(2)