Question 477765
rita's age is 3 times anna's. when anna is twice as old as she is now, rita's age will only be twice anna's. how old is each now?

Let A = Anna's age
   3A = Rita's age

2A = age of Ana A years from now
 
3A + A  = Rita's age when Ana's age is twice as old as she is now
        = 2(2A)

4A = 4A

A can be any positive number.

Meaning:
When Ana is 1 year old, Rita is 3 years old.
When Ana is 5 years old, Rita is 15 years old.
When Ana is 10 years old, Rita is 30 years old.

...and so on.