Set up an arithmetic function for the following scenario. Use the function the first ten terms of the sequence. An arithmetic sequence whose first term is -10 and the common difference is -2

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)