What is the sum of 0.5 and 0.3 ?

How many degrees does the hour hand move from 3: 00 to 5: 30?

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

Erin bought christmas cards for $2 each to send to her family and friends. which variable is the dependent variable?