Suppose a turtle walks 3/8 of a mile in 50 minutes What is the unit rate when the turtle’s speed is expressed in miles per hour (mph)?
A) 3/20 mph
B) 5/20 mph
C) 7/20 mph
D) 9/20 mph

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters