SOLUTION: Samantha is 6 years older than her brother. Four years ago she was 3 times his age, and last year she was twice his age. How old are Samantha and her brother?

Question 1061437: Samantha is 6 years older than her brother. Four years ago she was 3 times his age, and last year she was twice his age. How old are Samantha and her brother?
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
Hi there,
Samantha is 6 years older than her brother.
S = 6 + B........Eq(1)
Four years ago she was 3 times his age,
S - 4 = 3(B - 4).......Eq(2)
Last year she was twice his age.
S - 1 = 2(B - 1).......Eq(3)
...............
Substitute (6 + B) for S in Eq(2)
S - 4 = 3(B - 4).......Eq(2)
(6 + B) - 4 = 3(B - 4)
6 + B - 4 = 3B - 12
Collect like terms
B - 3B = -14
-2B = -14
B = 7
Substitute (6 + B) for S in Eq(3)
S - 1 = 2(B - 1).......Eq(3)
(6 + B) - 1 = 2(B - 1)
6 + B - 1 = 2B - 2
Collect like terms
B - 2B = -2 - 5
-B = -7
B = 7
Brother is 7 years old
Sister is 13 years old.
Hope this helps :-)
RELATED QUESTIONS
Christine is 6 years older than her brother scott. six years ago, she was twice his age.... (answered by ikleyn)

Christine is 6 years older than her brother scott. six years ago, she was twice his age.... (answered by ikleyn)

Zelma is 21 years older than her son. Two years ago she was four times his age. How Old... (answered by ewatrrr)

Sasha is 8 years older than her brother. Three years ago she was three times his age how... (answered by josgarithmetic)

1.Two years ago, Greg was 3 times as old as his brother. In four years, he will be only... (answered by AnlytcPhil)

You're four years older than your 18 year old sister. How many years ago were you three... (answered by Maths68)

1. If Samantha were three times as old as she was five years ago, she will be sixty less... (answered by josmiceli)

A man is n years old, 1.how old was he 12 years ago ? 2.his wife is 6 years older than... (answered by ikleyn)

samantha has an older brother right now he is twice her age but 8 years ago her brother... (answered by stanbon)