题目内容：

A girl has brother and sister.
she has as many brothers as she has sisters.
her brothers twice as many sisters as he has brothers.
How many children?
请看补充！A girl has brothers and sisters.
she has as many brothers as she has sisters.
her brothers twice as many sisters as he has brothers.
How many children?

优质解答

suppose x girls and y boys
x-1 = y
x= 2*(y-1)
x= 4
y= 3
x+y =7
There are 7 children