Question 141348: Phil and Phyllis are siblings. Phyllis has twice as many brothers as she has sisters. Phil has the same number of brothers as sisters. How many girls and how many boys are in the family?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Phil and Phyllis are siblings. Phyllis has twice as many brothers as she has sisters. Phil has the same number of brothers as sisters. How many girls and how many boys are in the family?
:
x = no. boys
y = no. girls
:
Phil: (x-1) bro, y sis
same number bro than sis:
(x-1) = y
x - y = 1
:
Phyl: x bro, (y-1) sis
Twice as many bro as sis:
x = 2(y-1)
x = 2y - 2
x - 2y = -2
;
Using these two equation for elimination
x - 2y = -2
x - y = 1
-------------subtracting eliminates x
0 - y = -3
y = 3 girls
:
We know x = 2y -2:
x = 2(3) - 2
x = 4 boys
:
Therefore:
Phil has 3 brothers, 3 sisters
Phyl has 4 brothers, 2 sisters
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