(UK St Paul's Girls School Sample Paper Section $A$ Question $$10$$)  Mary, Jess and Jo run a race.  Jess's time is $18$ seconds.  Jo finishes $6$ seconds before Jess.  Mary finishes $4$ seconds after Jo.  What is Mary's time in seconds? 
Overseas Competition->Knowledge Point->Word Problem Modules->Applying Addition and Subtraction->Simple Addition and Subtraction