Is 42/7 a rational or natural number

In one month jillian made 36 local phone calls and 20 long-distance calls what was her ratio of local calls to long-distance calls for that month?

:)i need to know on which ones are corresponding, alternate interior, alternate exterior, or none of these.

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)