Answer :
It means what is the time if it is one fourth or a quarter of an hour later than 5. one hour is 60 minutes and a quarter of an hour is 15 because 60/4=15. 5:00+:15=5:15
quarter past means 15 minutes past
example
''It's a quarter past 10'' - 10:15
half past means 30 minuets past
example
"It's half past 10" - 10:30
quarter till means 15 minuets till that hour
example
"It's a quarter till 11" - 10:45
Hope this helped :)