Question 787221
Jamie and Rosa are brother and sister.
b = no. of boys; g = no. of girls
 Jamie has the same number of brothers as dusters.
b - 1 = g
b = g + 1
 Rosa has twice as many brothers and sisters.
b = 2(g-1)
b = 2g - 2
 How many boys and girls are in the family?
b = b therefore
2g - 2 = g + 1
2g - g = 1 + 2
g = 3 girls in the family
then
b = 3 + 1
b = 4 boys
:
Not sure how many "dusters" were involved in this,
But generally it's the girls that worry about dust isn't it?