Lucia is a wonderful grandmother.Her age is b/w 50 to 70.Each of her sons have as many sons as they have brothers.Their combined number gives Lucia’s present age?what is her age?

• Explanation:
  The question basically states that if Lucia were to have say 10 sons, then each son would have 9 sons (Lucias grandsons - since each son has 9 brothers). So the total in this case would be 9××10 grandsons + 10 sons = 100.
  Let us assume Lucia has got x sons. Now each son has (x - 1) sons. So total = x + (x - 1) x. For x = 8 we get 64 which is in between 50 and 60. ( 7 x 8 grandsons + 8 sons = 64 ).
• 6 years agoHelpfull: Yes(6) No(1)
• 56 years
  
  Let grandmother has x sons, then each son have (x-1) brothers.
  So total number of sons and grandsons=Age of grandmother=x(x-1)=x² -x
  For x=8, we have x² -x=64-8=56 , which lies between 50 to 70.
  Hence grandmother's age=56 years.
• 6 years agoHelpfull: Yes(5) No(8)
• let the no.of Lucia's sons = x
  ==> each son has (x-1) brothers .
  no.of children of each son = (x-1)
  So, total no. of Lucia's grandchildren = x(x-1)
  Lucia's present age lies b/w 50 and 70
  therefore
  50< (x(x-1))+x < 70
  ==> 50 < x^2 < 70
  so x=8
  Lucia's present age = x^2=64
• 5 years agoHelpfull: Yes(2) No(0)
• If the brothers are x
  
  The number of sons = (x -1)x = x² - x
  
  The total number = x + x² - x
  
                              = x²
  
  A perfect square that lies between 50 and 70 is 64
  
  So Lucia (The grandmother) is 64 years old
• 5 years agoHelpfull: Yes(1) No(0)
• 56 as x*x-1 should be in range of 50-70
• 4 years agoHelpfull: Yes(0) No(2)