Question

A boy has as many sisters as brothers and his sisters have half as many sisters as brothers how many boys and girls are there in the family

Answer 1

the children in a family comprise both boys and girls. Each boy has as many brother as sisters, but each girl has half as many sisters as brothers. how many boys and how many girls are in the family.
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Let # of boys be "b".
Let # of girls be "g".
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Each boy has as many brothers as sisters
b-1 = g
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but each girl has half as many sisters as brothers.
g-1= (1/2)b
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Solve the the system of equations by substituting for "g":
b-1-1 = (1/2)b
b-2 = (1/2)b
(1/2)b = 2
b = 4 (# of boys)
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solve for "g":
b-1 = g
g = 4-1 = 3 (# of girls)
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Cheers,
Lehani