Radius of Amy's cylinder = 6/(2pi ) = 3/pi
Height of Amy's cylinder = 8
Radius of Belinda's cylinder = 8/(2pi) = 4/pi
Height of Belinda's cylinder = 6
Volume of Amy's cylinder = pi ( 3/pi)^2 ( 8) = 72/pi
Volume of Belinda's cylinder = pi ( 4/pi)^2 ( 6) 96/pi
Positve difference between the volumes = (96 - 72) / pi = 24 / pi