Boys and Girls Puzzle

The ratio of Boys and Girls Puzzle

In Boys and Girls Puzzle, in a country where everyone wants a boy, each family continues having babies until they have a boy. After some time, the proportion of boys to girls in the country is X: 1.

What is the value of X?

The ratio of Boys and Girls Puzzle

In Boys and Girls Puzzle, in a country where everyone wants a boy, each family continues having babies until they have a boy. After some time, the proportion of boys to girls in the country is X: 1.

What is the value of X?

Solution

Boys and Girls Puzzle

Here we have solution for this Puzzle – 

Number of girls = 0*(Probability of 0 girl) + 1*(Probability of 1 girl) + 2*(Probability of 2 girls) + …

  • Number of girls =
    0*(X*1/2) + 1*(X*1/2*1/2) + 2*(X*1/2*1/2*1/2) + …
  • Number of girls =
    0 + X/4 + 2*X/8 + 3*X/16 + …
  • Number of girls =
    X

    (Assume that the probability of having a boy or a girl is the same.)
    The proportion of boys to girls is 1: 1.

Solution

Here we have the solution for this Puzzle – 

Number of girls = 0*(Probability of 0 girl) + 1*(Probability of 1 girl) + 2*(Probability of 2 girls) + …

  • Number of girls = 0*(X*1/2) + 1*(X*1/2*1/2) + 2*(X*1/2*1/2*1/2) + …
  • Number of girls = 0 + X/4 + 2*X/8 + 3*X/16 + …
  • Number of girls = X
  • (Assume that the probability of having a boy or a girl is the same.)
  • The proportion of boys to girls is 1: 1.
Boys and Girls Puzzle

Prime Course Trailer

Related Banners

Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription

Get over 200+ course One Subscription

Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others

Checkout list of all the video courses in PrepInsta Prime Subscription

Checkout list of all the video courses in PrepInsta Prime Subscription