Interview Puzzles

Stack of 'must-know' interview puzzles !

Puzzle: Country of boys!!!

4964 views
In a country where people only want boys, every family continues to have children until they have a boy. if they have a girl, they go for another child. if they have a boy, they stop. what is the proportion of boys to girls in the country?
0 Vote Up   |   Post Answer   |   View Solution

By  Guest





Sangeeta Haldhar Sangeeta Haldhar   6 years ago

1:1

Reply    0 Vote Up   0 Vote Up
Sangeeta Haldhar Sangeeta Haldhar   6 years ago

Kind ofsum of infinite GP
a/(1-r)

1:1

Reply    2 Vote Up   0 Vote Up
Sangeeta Haldhar Sangeeta Haldhar   6 years ago

How the ratio comes to be 1:1 by using a/(1-r) ??

Reply    0 Vote Up   0 Vote Up


Deepak Aggarwal Deepak Aggarwal   5 years ago

1:1

Reply    0 Vote Up   0 Vote Up


Rajat Kumar Rajat Kumar   5 years ago

Ans.

Reason: girl boys
0 1
1 1
2 1
: :
: :
N 1

sum: N(N+1)/2 N+1

boys:girl 2:N or 1:N-1

Reply    0 Vote Up   0 Vote Up