Answer :
we have the equation
xy=20
where
y ----> is the time in hours
x ----> is the speed in miles per hours
so
y=20/x
using a graphing tool
The domain ---> Remember that the denominator cannot be equal to zero
so
x>0
The range
The graph has a vertical asymptote at x=0 and a horizontal asymptote at y=0
so
The range is the interval (0, infinite)
therefore
The answer is the option d
domain: x > 0; range: y > 0
You need a speed of about 2.5 miles per hour to travel 20 miles in 8 hours
