SOLUTION: The difference in ages between a boy and his younger brother is 6years.the younger brother is6 years older than his sister.the sum of ages if the younger brother and his sister is

Click here to see ALL problems on Age Word Problems

Question 1078526: The difference in ages between a boy and his younger brother is 6years.the younger brother is6 years older than his sister.the sum of ages if the younger brother and his sister is 30.how old are the three children?

Found 3 solutions by ankor@dixie-net.com, MathTherapy, josgarithmetic:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website!
let b = the boy's age
let y = the younger brother's age
let s = the sister's age
:
write an equation for each statement, arrange to have b and s in terms of y
;
The difference in ages between a boy and his younger brother is 6 years.
b - y = 6
b = y + 6
the younger brother is 6 years older than his sister.
y = s + 6
s = y - 6
the sum of ages if the younger brother and his sister is 30.
b + y + s = 30
replace b with (y+6), replace s with (y-6)
(y+6) + y + (y-6) = 30
combine like terms
3y = 30
y = 30/3
y = 10 yrs is younger bro's age
:
how old are the three children?
b = 10 + 6 = 16 yrs is the boy's age
and
s = 10 - 6 = 4 yrs is the sister's age
:
:
You can confirm this by finding the sum of the 3 ages

Answer by MathTherapy(10552)   (Show Source):
You can put this solution on YOUR website!

The difference in ages between a boy and his younger brother is 6years.the younger brother is6 years older than his sister.the sum of ages if the younger brother and his sister is 30.how old are the three children?

Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website!
b, boy
y, younger brother
x, younger sister

-

Elimination Method on the system in y and x:
-

-

.
.