SOLUTION: In a family, each boy has as many sisters as brothers, but each sister has only half as many sisters as brothers. how many children are in the family?

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Question 571502: In a family, each boy has as many sisters as brothers, but each sister has only half as many sisters as brothers. how many children are in the family?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Count the boy as 1
(1) +b+-+1+=+s+ is what the boy sees
Count each sister as 1
Each sister sees +s+-+1+ of her sisters
For her,
(2) +b+=+2%2A%28+s+-+1+%29+
-----------------------------
(2) +b+=+2s+-+2+
Substitute (1) into (2)
(2) +b+=+2%2A%28+b+-+1+%29+-+2+
(2) +b+=+2b+-+2+-+2+
(2) +b+=+4+
and
(1) +b+-+1+=+s+
(1) +4+-+1+=+s+
(1) +s+=+3+
------------------
There are 4 bothers and 3 sisters,
or 7 children
This works