A grandma has many sons; each son has as many sons as his brothers. What is her age if it?s the product of the no: of her sons and grandsons plus no: of her sons?(age b/w 70 and 100).

• Let N be number of sons to grandma. Then according to question (N-1) children to each son of grandma.Now
  Age of grandma=(no. of grandma son's)*(no. of grandsons)+ no. of grandma son's
  = N * [N*(N-1)] + N
  Putting N=1,2,3,4,5
  We get Age of grandma=52 , when N=4 and
  Age of grandma=105 ,when N=5
  Hence no solution between 70 and 100.
• 12 years agoHelpfull: Yes(10) No(6)
• What Mr.Naunihal Maurya said is right. If grandma age is in b/w 70 and 100,The question should be like following....
  A grandma has many sons; each son has as many sons as his brothers. What is her
  age if it?s the product of the no: of her sons and grandsons of each son plus no: of her sons?(age b/w 70 and 100).
  
  nw the answer is.... (9*8)+9=81
• 10 years agoHelpfull: Yes(7) No(0)
• @ Imran,
  Pls check your statement
  
  'therefore (4*12)+(total sons=4)=68+4====72.....'
  
  4*12= 48 and not 68.
  
  I think given data is not correct.
• 12 years agoHelpfull: Yes(6) No(1)
• Let N b the no of son. Then acc. To d question each son has N-1 Son(no.of their bro)
  So N*N(N-1) is d age of d gandma
  By putting
  N=1,2,3,4&5
  So when n=5
  Gandma's age is 100(b/w 70 to 100)
  So ans is 100 years
• 12 years agoHelpfull: Yes(2) No(9)
• consider grandma has 4 sons
  total grandsons=12(because each son has as many sons as his brother) so 4*3=12
  therefore (4*12)+(total sons=4)=68+4====72.....
  Ans 72
• 12 years agoHelpfull: Yes(1) No(14)
• 81 is correct
• 7 years agoHelpfull: Yes(1) No(0)
• the answer to dis question mentioned everywhere is 81...but i dont know the solution..... AND WHAT I THINK IS THE EQUATION SHOULD BE N*N(N-1)+N........ BCOZ ITS WRITTEN IN THE QUESTION THAT "PLUS THE NUMBER OF HER SONS"........... PLZZZ HELP
  Update 2: MAY BE ITS THIS WAY....
  
  grandma has x sons...those x sons in total have (x-1) sons... so the equation would be now..
  
  x(x-1)+x
  #x(sqaure)........and to satisfy the condition of her being btw 70 and 100..only 9 should be the number...
  hence 9(square) is 81.........
• 7 years agoHelpfull: Yes(1) No(0)