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 :)