Lee is $14$ years old and Lay is $41$ years old. How many years ago, Lay\textquotesingle s age is exactaly $4$ times Lee\textquotesingle s age? 
Overseas Competition->Knowledge Point->Word Problem Modules->Equation Word Problems
Let the year be $x$ years ago.  $14-x=(41-x)\div 4$  $4(14-x)=41-x$  $56-4x=41-x$  $15=3x$  $3x=15$  $x=5$ 