SOLUTION: Lisa will be twice as old as her brother Ralph in 6 years. Lisa was three times as old as Ralph 3 years ago. What are their ages now?

Question 681040: Lisa will be twice as old as her brother Ralph in 6 years. Lisa was three times as old as Ralph 3 years ago. What are their ages now?
Answer by htmentor(1343) (Show Source): You can put this solution on YOUR website!
Lisa will be twice as old as her brother Ralph in 6 years. Lisa was three times as old as Ralph 3 years ago. What are their ages now?
==================
Let L = Lisa's current age
Let R = Ralph's current age
In 6 years Lisa will be twice her brother's age:
L+6 = 2(R+6)
L = 2R + 12 - 6
L = 2R + 6
3 years ago Lisa was 3 times her brother's age:
L-3 = 3(R-3)
(2R+6)-3 = 3R - 9
This gives R = 12
So Ralph is 12 yrs old and Lisa is 2*12 + 6 = 30 yrs old
RELATED QUESTIONS
Lisa will be twice as old as her brother Ralph in 6 years. Lisa was three times as old as (answered by ptaylor)

Ralph is four times as old as Frank. In 20 years, Ralph will be twice as old as Frank.... (answered by terrtwo)

Ralph is 3 times as old as Sara. In 6 years, Ralph will be only twice as old as Sara will (answered by TimothyLamb)

ralph is 21 and aunt lisa is 76. how many years ago was aunt lisa exactly 6 times as old... (answered by Alan3354)

Ralph is 3 times as old as Sara. In 6 years, Ralph will be only twice as old as Sara will (answered by josmiceli)

Five years ago, John was three times as old as Lisa and in ten years from now John shall... (answered by htmentor)

Four years ago, Lisa was twice as old as John. Four years from now, John will be three... (answered by Fombitz)

Fourteen years ago, Ralph was one-third as old as he will be 8 years from now. How old... (answered by ankor@dixie-net.com)

Lisa will be half as old as her brother in five years. How old will she be in seven... (answered by lwsshak3)