The age of the grandlady  is between 50-70 where each of her son has as many sons as many brothers he has.The grand lady's age is equal to the number of sons and grand sons.What is the age of the grand lady.

ha

• Sep 1st, 2005

 

Ans: 64 .. 
because if there are 7 sons, each of the seven sons will have 6 sons ie total no  
of grandsons = 42 and sons=7 and 42+7<60 
not valid 
But when u try it asuming there are 8 sons  
you get a valid age (56 grandsons and 8 sons) 

premsagar

 Profile Answers by premsagar 

• Oct 4th, 2005

 

answer 64 is correct.

lets say grandlady has n chlidren so each child will have n-1 children.

so total is n+(n*(n-1)) so substitue 8 in this formula you will get 64.

shilpa

• May 12th, 2006

 

let grand lady hav "x" sons.so each of the sons vil hav "x-1"sons.age of grlad isx+x(x-1)=x62.the only sq num between 50 and 70 is 64.her age is 64

malathi

• Aug 22nd, 2007

 

64 only
if it was 7 sons the age of grandlady will be 49 which is not between 50-70 therefore 8*8=64 which falls between 50-70

prathap5987

 Profile Answers by prathap5987 

• Nov 28th, 2009

 

They have 8 sons and 8 grandsons, so total is 64

manojthesingham

 Profile Answers by manojthesingham 

• Dec 4th, 2009

 

Consider grandma has 2 sons then each son will have 1 son each

     (grandma)

 (son1)   (son2) 

(gson1) (gson2)

Consider grandma has 3 sons then each son will have 2 son each

                                       (grandma)

         (son1)                     (son2)                 (son3)   

(gson1) (gson11)  (gson2) (gson22)  (gson3)(gson33)

son gson age

 2   2  4

 3   6  9

 4  12 16

it goes like n^2 therefore 64 is between [50 to 70]