Suppose Mr. Baumler gets to pick 2 candies from a bucket without looking and in the bucket are kitkat, and 3 bags of M&Ms. What is the probability that he picks a bag of M&Ms on his first pick or a twix on his second pick

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