A coffee shop owner blends a gourmet brand of coffee with a cheaper brand. The gourmet coffee usually sells for $10.00 per pound. The cheaper brand sells for $4.00 per pound. How much of each type should be mixed in order to have 30 pounds of coffee that is worth $7.50 per pound?

Average acceleration: i have no idea how to do this.

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

Answer! if you don’t mind, can you explain