jane and olivia both celebrate their birthday today. In three years, jane
will be four times as old as olivia was when jane was two years older than
olivia is today. If olivia is a teenager, how old is jane now?
This is a nice problem that I found while looking through the oldies here. I know this has already been answered by Jane which seems apt. I still enjoyed working on it.
We call the variables:
Agediff - the difference between Jane's and Olivia's ages.
Jage Jane's age now, what we want.
Oage Olivia's age now.
Jthen Jane's age then ( 2 years older than olivia is now )
Othen Olivia'a age when Jane was 2 years older.
We get the following equations.
Easy to solve:
Jage = Jane's age = 25
Oage = Olivia's age = 15
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.