What is the estimated sum of an orange that costs $0.69 and a hot pepper that costs $0.15 if their prices are rounded to the nearest ten cents and then added together?
(a)$0.70
(b)$0.80
(c)$0.90
(d)$1.00

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