calculate ages of all

Replies

• 

  4M4N

  kishu=9, reema=18, sudha=21, seema=18, sonny=12 and sareen=39,
  correct me if wrong
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  Ankita Katdare

  @4M4N: Please put the explanation or solving process.
• 

  Manish Goyal

  Please explain the answer
• 

  4M4N

  sorry friends, i jst read the answer from a book , no explanation was given there
• 

  makru921

  25 minutes and all i have is a bunch of nonsensical equations😔 Hope somebody can explain it if there is a correct answer..
• 

  Ankita Katdare

  @Makru: Same here.
  I am not able to build a relation between the equations.
• 

  Saandeep Sreerambatla

  This is not a direct question which can be solved by equations.
  
  We need to solve this using equations and by probable substitutions.
  
  I got the solution after 1 hour of work, nice question goyal.
  
  And yes, the answers are correct.
• 

  Saandeep Sreerambatla

  Now let us assume the ages of everyone for variables.
  
  Sareen = M , sudha = X , seema = Y , Reema = Z , sonny = a and Kishu = b.
  
  Now few points to be noted are, Sonny age will be between 10 - 15 and that of Kishu will be below 10.
  
  Now from the condition 1:
  
  1/2(M-15) = X + Y+ Z - 45
  which comes down to
  
  M = 2(X + Y+ Z)-75 -----------------------------(1)
  
  For condition 2:
  
  M-10 = X + Y+ Z-30 + a – 10
  
  Substituting 1 in the above equation we get
  
  M = 2a + 15 -----------------------------(2)
  
  
  Now from another condition ,
  
  X + Y+ Z+a+b = 2M
  
  And M = X+Y and X = a+b (all given)
  
  Now, M+Z+X = 2M (a+b = X)
  
  So, X+Z = M
  
  And we also know that X + Y = M , which results in Y = Z.
  
  So which states that Seema and Reema are twins and also states that Sudha is the eldest.
  
  Now 1 will be modified as ,
  
  M + 75 = 2(X + Y+ Z) , since X + Y = M
  
  M + 75 = 2M + 2Z which gives
  
  2Z = 75 – M ----------------------(F1)
  
  Now, we go back to the equation 2.
  
  As already stated Sonny’s age will be in 10 – 15, his age will be 11, 12, 13 and 14.
  
  2(11) + 15 = M = 37
  
  Putting this in F1 , will give Z = 19 , and Y = 19 as Y and Z are twins.
  
  This results in X = 18 which is incorrect as Sudha is eldest.
  
  Now, we will substitute Sonny’s age as 12.
  
  Which results in M = 39
  
  Which gives , Z = Y = 18
  
  And X = 21
  
  And X = a+b , which gives b = X – a = 21-12 = 9 J
  
  Hence got the solution.
  
  All other values of Sonny will result in b > 10 which is not valid.
  
  Hope everyone understood.
• 

  Ankita Katdare

  @ES: That was simply superb! You've got a knack. 😀
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  Sahithi Pallavi

  Fantastic ES! You are superb! 😀
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  makru921

  Wow.. impressive! I reached the equations stage but then dint bother to substitute and all.. Got lazy😀 But this is perfectly done and explained.. Good job ES😀
• 

  Reya

  @ES:Hats off to you!I was trying for a long time!