A hollow iron pipe is 42 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 3 g/cm3, then the weight of the pipe is: Options
A) 2.172 kg
B) 2.272 kg
C) 2.282 kg
D) 2.992 kg
E) 2.772 kg
External radius = 4 cm,   Internal radius = 3 cm.   Volume of iron	=22/7x ((4 SQUARE)-(3 SQUARE))X42   =(22/7)X7X1X42 cm3.   = 924cm3.   Weight of iron = (924 x 3) gm = 2772 gm = 2.772 kg   answer :2.772 kg
<result>E</result>
A hollow iron pipe is 42 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 3 g/cm3, then the weight of the pipe is: