How many brothers and sisters? from AVRamani's blog

A friend sent this puzzle:

A family I know has several children. Each boy in this family has as many sisters as brothers but each girl has twice as many brothers as sisters. How many brothers and sisters are there?

I know it is trivial. Still as they say in Telugu ‘ Poyindemitti?’ Meaning what is lost?

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AVRamani
Oct 31
Since I posted the puzzle, the answer has to be too:
AVRamani
Oct 31
Let s be the number of girls and b the boys.
1. Now, each girl has twice as many brothers as sisters. This means:
2x( s-1) = 2s - 2 = b
2. Each boy in this family has as many sisters as brothers. This means:
b-1 = s or b=s+1
This means: 2s-2 = s+1
from which 2s-s = 1+2 = 3
therefore b = s+1 = 3+1 = 4

So there are 3 girls and 4 boys in the family.
Let s be the number of girls and b the boys.
1. Now, each girl has twice as many brothers as sisters. This means:
2x( s-1) = 2s - 2 = b
2. Each boy in this family has as many sis...See more
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By AVRamani
Added Oct 29

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