$15$ minutes past $5:00$ PM is $5:15$ PM. 
Math workshop starts at $5:00$ PM. Today Allan was $15$ minutes late to the workshop. What time did Allan come? (2010 Math Kangaroo Problem, Level 1--2, Question \#12) 

  $5:00$ PM 
  $5:05$ PM 
  $5:15$ PM 
  $5:20$ PM 