Which group of numbers could be placed in section B?

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Use the distributive law to multiply. 3(4x + 5y + 6)

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