Answer:
180 minutes
Explanation:
Starting with the distance formula ...
d = rt
dividing by the coefficient of t will give an equation for t:
t = d/r
Ryan's rate of 4 miles per hour can be expressed in minutes as 4 miles per 60 minutes. The Ryan's time is ...
t = (12 mi)/(4 mi/60 min) = 12·60/4 min = 180 min
Ryan's time is 180 minutes.