True or false? if a number is divisible by 2, then every digit of the number is divisible by 2.

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

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?

Find the distance between the pair of points a(-1,8) and b(-8,4)