On Kellin\textquotesingle s $$13$$th birthday, Allen was four times her age. On Kellin\textquotesingle s $$24$$th birthday, how old was Allen? 
Overseas Competition->Knowledge Point->Word Problem Modules->Age Problems->Basic Relationships in Age Problems
On Kellin\textquotesingle s $$13$$th birthday, Allen was four times her age, that is $$52$$. It is then eleven years until Kellin\textquotesingle s $$24$$th birthday, so Allen\textquotesingle s age at that time was $$52 +11 =63$$. 