SOLUTION: My daughter is having a tough time with this equation. Fifteen years ago, Alberto was twice as old a Rosa. In nine more years, he will be twice as old as she was when he was a

Question 129733: My daughter is having a tough time with this equation.
Fifteen years ago, Alberto was twice as old a Rosa. In nine more years, he will be twice as old as she was when he was as old as she is now. How old is Rosa?
Any help is appreciated.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
All of these type problems can be solved this way:
Let = Alberto's age now
Let = Rosa's age now
In order to talk about their ages 15 years ago,
you have to subtract 15 from EACH of their ages

The next part is very tricky, and I sort of
take it one or two words at a time
It's about Alberto in 9 more years. That's

He's going to be twice as old as something, so
I've got = 2 x ?
Now I've got the brain-twister
"twice as old as she was when he was as old as she is now."
I can grapple with it better if I put actual numbers on their
ages, just for now.
Say he is 10 and she is 6 now
4 years ago he was 6 like she is now. Call this age

because is her age now, or 6 years old
This is "when he was as old as she is now."
Now how old was she?

This is "as old as she was", or
Now I put it all together

(1)
and from above,

(2)
multiply (2) by and subtract from (1)

Alberto's age now

Rosa's age now
check answers

OK
whew!
RELATED QUESTIONS
Ten years ago, the sum of the ages of a mother and her daughter was seventy years. This... (answered by josgarithmetic,MathTherapy)

Mr.Munch is twice as old as his daughter. In two years, he will be four times as old as... (answered by lwsshak3)

In 10 years time a father will be twice as old as his daughter.10 years ago he was six... (answered by ikleyn)

Mr. Munch is twice as old as his daughter. In two years, he will be four times as old as... (answered by stanbon,DrBeeee)

five years ago, a mother was six times as old as the daughter. this year the daughter is... (answered by josgarithmetic)

A mother is three times as old as her daughter. Nine years ago, she was six times as old... (answered by josmiceli,mananth)

6 years ago, rosa was 4 times as old as her daughter. 10 years from now, she will be only (answered by mananth)

six years ago, rosa was four times old as her daughter. Ten years from now, she will be... (answered by mananth)

a father is now twice as old as his daughter. Ten years ago he was three times as old as... (answered by ewatrrr)