Help with this iready please.

Mr. t has been dating his girlfriend for one year nine months and six days how many hours has mr. t been in a relationship

Ihave like no idea how to do any of this !

Sound travels about 750 miles per hour. a) suppose it takes about 1.5 seconds to hear the echo. how far away is the canyon wall, in feet? for this i got 825 ft b) suppose you stand 1,925 feet from the canyon wall and sound the horn. how long will it take to hear the echo? (i'm stuck on this)